The math department recently purchased new learning software for their freshman math classes. The instructors want to use the learning software instead of a textbook. So they decide to study the effectiveness of the software. First they test the skills and concept mastery for a number of the freshman math students. Then they randomly divide the students into two groups. One group uses the learning software for a particular lesson and the other group uses the regular textbook. Then the instructors retest all of the students and compare the improvement in the skills and concept mastery for the two groups. What is the purpose of random assignment in this experiment? Check all that apply.

Answers

Answer 1

Options :

A.) To avoid bias

B. To control for confounding variables

C. To produce treatment groups with similar characteristics

D. To generalize the experiment results to all freshman math students

Answer:

To avoid bias

To generalize the experiment results to all freshman math students

Step-by-step explanation:

One of the most common problems with statistical experimental research is the issue posed by bias. Either selection bias or assignment bias. Bias creeps into our experiment when one experimental group is more favored than the other. This means that the strategy employed is not totally random. In the experimetal design explained above, students were randomly assigned to group in other to avoid bias. This random assignment ensures that all samples have equal probability of being assigned to any of the two groups.

Randomized experimental designs also allows for making a good estimate of the population parameter fromnthe sample statistic


Related Questions

A local country club has a membership of 600 and operates facilities that include an 18-hole championship golf course and 12 tennis courts. Before deciding whether to accept new members, the club president would like to know how many members use each facility. A survey of the membership indicates that 75% use the golf course, 50% use the tennis courts, and 5% use neither of these facilities. One club member is chosen at random. What is the probability that the member uses the golf course but not the tennis courts

Answers

Answer:

0.45 = 45% probability that the member uses the golf course but not the tennis courts

Step-by-step explanation:

I am going to solve this question using the events as Venn sets.

I am going to say that:

Event A: Uses the golf courses.

Event B: Uses the tennis courts.

5% use neither of these facilities.

This means that [tex]P(A \cup B) = 1 - 0.05 = 0.95[/tex]

75% use the golf course, 50% use the tennis courts

This means, respectively, by:

[tex]P(A) = 0.75, P(B) = 0.5[/tex]

Probability that a member uses both:

This is [tex]P(A \cap B)[/tex]. We have that:

[tex]P(A \cap B) = P(A) + P(B) - P(A \cup B)[/tex]

So

[tex]P(A \cap B) = 0.75 + 0.5 - 0.95 = 0.3[/tex]

What is the probability that the member uses the golf course but not the tennis courts?

This is [tex]P(A - B)[/tex], which is given by:

[tex]P(A - B) = P(A) - P(A \cap B)[/tex]

So

[tex]P(A - B) = 0.75 - 0.3 = 0.45[/tex]

0.45 = 45% probability that the member uses the golf course but not the tennis courts

Which of the following are true statements? Select two that apply.

Answers

Answer:

Options A and C are correct answers

Step-by-step explanation:

A) [tex] \angle 5\: and \:\angle 1[/tex] are complementary.

C) [tex] \angle 3\: and \:\angle 4[/tex] form a linear pair.

Hope it helps you in your learning process.

Answer this correctly I’ll give brainalist + 10 points

Answers

The Answer is 66

That small little box there that’s 90

You subtract 90 with 24 and you should get 66
The answer to your asked question is 66, 90-24=66. Hope this helped have a good day/night!

Allison had 310 rocks in the rock collection after three months, her collection increases by 40% how many rocks does she have now?

Answers

Answer:

434

Step-by-step explanation:

310 times .4 (percentage) = 124 which is how much she gained, then you add that onto the original amount to find how many she has now, which is 434

Use the distance formula to find the distance between (2,1) and (6,8). Round to the tenths place. thats the question there isn't any picture or graph

please help!:(

Answers

6 8. Sorry if wrong

Sally earns graduated commission on her sales each month. She earns 6% commission on the first $45,000 in sales and 8% on anything over that. If Sally had $51,000 in sales this month, how much commission did she earn?
a.
$4,080
b.
$3,180
c.
$3,060
d.
$2,820

Answers

The answer is B, because 0.06*45000 + 0.08(51000-45000) = 3,180

Answer:

Sally earns graduated commission on her sales each month. She earns 6% commission on the first $45,000 in sales and 8% on anything over that. If Sally had $51,000 in sales this month, how much commission did she earn?

a. )  $4,080 b. )  $3,180 <<<CORRECT c. )  $3,060 d. )  $2,820

Step-by-step explanation:

Edge 2021

There are three numbers for the combination to the store's safe. The first number is 17. The two numbers can be multiplied together to give a product of 28. What are all of the possibilities for the other two numbers? IT IS MULTIPLICATION BTW

Answers

Answer:

1 28

2 14

4 7

Step-by-step explanation:

7 4

14 7

28 1

...........

16. On a yachting trip in the South Pacific, you discover a previously unknown island. You notice that there is a population of especially fluffy and particularly cute long-eared rabbits living there. These rabbits seem to have no predators at all on the island, and their mating habits seem to be perfectly random. When they are first surveyed, they have an average ear length of about 18 cm. When they are sampled again in five years, what will likely be true of their ear length

Answers

Answer: Their ear length will be thesame because there's no force of evolution.

Step-by-step explanation:

Based on the information given in the question as we are informed that the rabbits have no predators and that their mating habits seem to be perfectly random.

We should note that when they are sampled again in five years, due to the fact that there's no source of evolution, their ear length will be thesame. Also, their offspring number will be thesame as well.

7x10+2x1+6x1/10+3x1/1000

Answers

Answer:72.603

Step-by-step :

70 + 2 + 6 ÷ 10 + 3 ÷ 1000

=72.603

Rashads teacher buys paperback books for her classroom library. Each book costs $6, and she spends a total of $150. Which equation models the number of books, n, she buys? A. 6n=150 B. n/6=150 C.150-n=6 D. 6•150=n

Answers

Answer:

A  

Step-by-step explanation:

6n=150

270 because yea hahahahaha

A rectangle has a length of (x+3) feet and a width of 1/2x feet.
If the perimeter is 21 feet, what is the length of the rectangle?

Answers

the length of the rectangle is 8 feet. X = 5

Type the answer in the box.

d = 6 y = 10 g = 8

Answers

Step-by-step explanation:

[tex](6) + \frac{1}{2} (10 + 8)[/tex]

[tex]6 + \frac{1}{2} (18)[/tex]

[tex]6 + \frac{18}{2} [/tex]

[tex]6 + 9[/tex]

[tex]15[/tex]

Answer:

15

Step-by-step explanation:

an electronics store is having a 20%-off on all cell phones. the original price of a cell phone is x dollars. which expression represents the sale price of a cell phone?

a. x - 0.2
b. x - 0.8
c. 0.2*x
d. 0.8*x​

Answers

Answer: x*.2

Step-by-step explanation:

When you are trying to find the sale price you want to multiply the origanal price of the cellphone to the percentage you are getting off. Hope this helped!

The number of that grow sugar beet =12

Answers

Answer:

I think question is not proper

you should check it again

hope your day will fine

Answer:

Whatttt

Step-by-step explanation:

what are prime factors

Answers

Answer:

Prime Factors is a  factor of a given integer which is also a prime number.

numbers like 9, 13, 7 and etc

Consider the function graphed below.

What is the average rate of change of the function over the interval [1, 3] ?

A.36

B. 48

C.72

D.96

Answers

Answer:

A. 96

Step-by-step explanation:

By using slope formula we got that  average rate of change of the function over the interval [1, 3] is 48 .

What is the average rate of change?

the rate at which one variable of a function changes in relationship to another variable  is called average rate of change.

Here we can see in graph that

when x =1 y=12

and when x= 3 ,y=108

Now we know that rate of change is same as slope of straight line passing through that points

So average rate of change can be calculated as

[tex]=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]

[tex]=\frac{108-12}{3-1}\\\\[/tex]

[tex]\frac{96}{2}[/tex]

=48

By using slope formula we got that  average rate of change of the function over the interval [1, 3] is 48 .

To learn more about rate of change visit :https://brainly.com/question/8728504

Three different methods for assembling a product were proposed by an industrial engineer. To investigate the number of units assembled correctly with each method, 30 employees were randomly selected and randomly assigned to the three proposed methods in such a way that each method was used by 10 workers. The number of units assembled correctly was recorded, and the analysis of variance procedure was applied to the resulting data set. The following results were obtained: SST = 10,800; SSTR = 4560.
Set up the ANOVA table for this problem (to 2 decimals, if necessary).
Source of Variation Sum of Squares Degrees of Freedom Mean Square F
Treatments
Error
Total
Use {Exercise 13.07} Three different methods for assem = .05 to test for any significant difference in the means for the three assembly methods.
Calculate the value of the test statistic (to 2 decimals).
The p-value is Selectless than .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 11
What is your conclusion?
SelectConclude not all means of the three assembly methods are equalCannot reject the assumption that the means of all three assembly methods are equal
Item 12are my calculations correct?

Answers

Given :

Number of methods, k = 3

Number of the observations, n = 30

Degrees of freedom Treatment = k - 1

                                                     = 3 - 1 = 2

Degrees of freedom for error = n - k

                                                 = 30 - 3 = 27

[tex]$SSTR = 4560, \ SST = 10800$[/tex]

[tex]$SSE = SST - SSTR$[/tex]

       = 10800 - 4560

       = 6240

[tex]$SSE_{treatment} = MS_{treatment } \times DF_{treatment}$[/tex]

[tex]$MS_{treatment} = \frac{4560}{2}=2280$[/tex]

[tex]$MS_{error}=\frac{SSE_{error}}{DF_{error}}$[/tex]

             [tex]$=\frac{6240}{27}=231.1$[/tex]

[tex]$F=\frac{MS_{treatment}}{MS_{error}}$[/tex]

  [tex]$=\frac{2280}{231.1}=9.865$[/tex]

Source variation   Sum of square  Degrees of freedom  Mean square     F

Treatment                   4560                          2                         2280       9.8653

Error                            6240                         27                   231.11111111

Total                            10800

The critical value of F for the 0.05 sig level and df (227) is 3.354

Since the test stat > critical value of F, so we reject null hypothesis and state that there is a significant difference in the means of the three assembly methods.

At the Demarest Mountain ski slope lounge, they serve hot cocoa. A serving of
hot cocoa uses 1 and a half tablespoons of cocoa. The large jar holds 90
tablespoons of cocoa mix, but the jar is half empty. How many more servings of
Hot Cocoa can they give out?

Answers

Answer: 30 more servings

Explanation:
They had 90 tablespoons, but half are gone. 90/2 = 45

Each serving is 1.5 tablespoons.

45/1.5 = 30 more servings
The answer is 30 more servings

Find each product mentally, using the distributive property, 4x51/8. (giving brainliest)

Answers

Answer:

25.5

Step-by-step explanation:

4 x 51 / 8

204/8

25.5

Answer:

Step-by-step explanation:

4×15/8 = 4×(1+⅞) = 4×1 + 4×⅞ = 4 + 7/2 = 4 + 3.5 = 7.5

Please help
A 136
B 208
C 352
D 576

Answers

I believe it’s C. Have a good day. Hope this helps.

Answer im not in grade

Step-by-step explanation:

4) Let a represent "x is a multiple of 3".
Let b represent "x is odd".
When x is 36, which of the following is true?

Answers

Step-by-step explanation:

When x=36, only the first statement is true (x is a multiple of 3). this is because 12×3= 36

36 is not odd, making the other statement false

^^^^this is correct

Pls help me show work too:(

Answers

x=2.5 the triangles are 2x the scale of the other one so if you divide the numbers on the triangle by 2 then you will get the answer for x

The total weight of 9 bags of potatoes is 36 kilograms each bag weights the same amount what is the weight in grams of each bag of potatoes

Answers

Answer:

4000

Step-by-step explanation:

36kg = 36000g

36000g/9 bags = 4000g

The weight of one bag of potatoes is 4 Kg,

What is Unitary Method?

The unitary technique involves first determining the value of a single unit, followed by the value of the necessary number of units.

For example, Let's say Ram spends 36 Rs. for a dozen (12) bananas.

12 bananas will set you back 36 Rs. 1 banana costs 36 x 12 = 3 Rupees.

As a result, one banana costs three rupees. Let's say we need to calculate the price of 15 bananas.

This may be done as follows: 15 bananas cost 3 rupees each; 15 units cost 45 rupees.

Given:

The total weight of 9 bags of potatoes is 36 kilograms.

Then, weight of one bag of Potato is

= 36/9

= 4 Kg

Thus, One bag weigh 4 Kg.

Learn more about Unitary Method here:

https://brainly.com/question/30129918

#SPJ6

The sum of 6 times a number and 4 is 9

Answers

5/6 is the correct answer
5/6 is the answer I think as well

PLEASE HELP !! ILL GIVE BRAINLIEST *EXTRA 40 POINTS* DONT SKIP :(( .!

Answers

Answer:

B) one solution

Step-by-step explanation:

to understand thisyou need to know about:linear equationPEMDAStips and formulas:[tex]\sf\text{a system of linear equation has only one solution if $\frac{a_1}{a_2}\neq \frac{b_1}{b_2}$}[/tex]given:[tex] \begin{cases}2x - 4y = - 1 \\ 8x - 11y = - 19 \end{cases}[/tex]let's solve:

[tex] \sf substitute \: the \: value \: of \: a \: b : \\ \frac{2}{8} \ne \frac{ - 4}{ - 11} \\ [/tex]

[tex]\text{$\therefore$ the system of linear equation has only one solution}[/tex]

5th grade math. correct answer will be marked brainliest.

Answers

Answer:

1

12 ------

3

5x + 4 = 3x + 10 how would you solve for the value of x? How would you prove your solution is correct? How would you prove another value is incorrect? Explain in as much detail as possible.

Answers

5x+3=3x+10 the first thing we're going to do it to subtract 3 from both sides which would look like this

5x+3-3x=10 (the minus because it changed place)

from 5x and 3x we get 2x so the next step is 2x=10-3 which is 7

so now we have

2x=7

x=7/2

Answer:

x=3

Step-by-step explanation:

5x+4 = 3x+10

2x = 6

therefore, x = 3

Verification:

5 * 3 + 4 = 3 * 3 + 10

15+4 = 9+10

19=19

Therefore, LHS= RHS

Hence Proved!

First one to answer gets BRAINLIEST no cap look at the picture.

Answers

Answer:

your answer will be 56 square millimeters

Step-by-step explanation:

hope it helps

Answer:

34 square meaters.

Step-by-step explanation:

Look at picture below!

An elementary school is offering 3 language classes: one in Spanish, one inFrench, and one in German. The classes are open to any of the 100 students inthe school. There are 28 students in the Spanish class, 26 in the French class,and 16 in the German class. There are 12 students that are in both Spanish andFrench, 4 that are in both Spanish and German, and 6 that are in both Frenchand German. In addition, there are 2 students taking all 3 classes.(a) If a student is chosen randomly, what is the probability that he or she isnot in any of the language classes

Answers

Answer:

0.5 = 50% probability that he or she is not in any of the language classes.

Step-by-step explanation:

We treat the number of students in each class as Venn sets.

I am going to say that:

Set A: Spanish class

Set B: French class

Set C: German class

We start building these sets from the intersection of the three.

In addition, there are 2 students taking all 3 classes.

This means that:

[tex](A \cap B \cap C) = 2[/tex]

6 that are in both French and German

This means that:

[tex](B \cap C) + (A \cap B \cap C) = 6[/tex]

So

[tex](B \cap C) = 4[/tex]

4 French and German, but not Spanish.

4 that are in both Spanish and German

This means that:

[tex](A \cap C) + (A \cap B \cap C) = 4[/tex]

So

[tex](A \cap C) = 2[/tex]

2 Spanish and German, but not French

12 students that are in both Spanish and French

This means that:

[tex](A \cap B) + (A \cap B \cap C) = 12[/tex]

So

[tex](A \cap B) = 10[/tex]

10 Spanish and French, but not German

16 in the German class.

This means that:

[tex](C - B - A) + (A \cap C) + (B \cap C) + (A \cap B \cap C) = 16[/tex]

[tex](C - B - A) + 2 + 4 + 2 = 16[/tex]

[tex](C - B - A) = 8[/tex]

8 in only German.

26 in the French class

[tex](B - C - A) + (A \cap B) + (B \cap C) + (A \cap B \cap C) = 26[/tex]

[tex](B - C - A) + 10 + 4 + 2 = 26[/tex]

[tex](B - C - A) = 10[/tex]

10 only French

28 students in the Spanish class

[tex](A - B - C) + (A \cap B) + (A \cap C) + (A \cap B \cap C) = 16[/tex]

[tex](A - B - C) + 10 + 2 + 2 = 28[/tex]

[tex](A - B - C) = 14[/tex]

14 only Spanish

At least one of them:

The sum of all the above values. So

[tex](A \cup B \cup B) = 14 + 10 + 8 + 10 + 2 + 4 + 2 = 50[/tex]

None of them:

100 total students, so:

[tex]100 - (A \cup B \cup B) = 100 - 50 = 50[/tex]

(a) If a student is chosen randomly, what is the probability that he or she is not in any of the language classes?

50 out of 100. So

50/100 = 0.5 = 50% probability that he or she is not in any of the language classes.

WILL MARK BRAINLEIST HELPP PLEASEEEE

Answers

the answer is x=15. pls give me brainliest :)

Answer:

15

Step-by-step explanation:

9x + 25 + x + 5 = 180

Add numbers = (25 + 5 = 30)

9x + 30 + x = 180

Combine like terms = (9x + x = 10x)

10x + 30 = 180

Subtract 30 from each side (10x + 30 - 30 = 180 - 30)

10x = 150

Divide 10 from each side (10x/10 = 150/10)

x = 15

Other Questions
Jamie collected some data on students' average grades and the average number of hours they spend playing video games and found there was a weak negative correlation. Which r value is most likely for this data? plz help wit 1 3 4 i What is the main gas in our atmosphere? Graph the line with the equation y = 1/5x-3 Question 16How does the skeletal system interact with the nervous system?A the nervous system supplies the blood and oxygen to developing bonesBthe nervous system supplies nutrients and minerals to developing bonesthe skeletal system controls the messages sent to the brain and spinal cordDthe skeletal system provides protection for the brain and spinal cord eight values have a mean of 7. a ninth value is added. the new mean is 9. what is the new value __________________________ You are flying a drone at a height of twelve yards. It has traveled a horizontal distance of twenty-eight yards. What is the angle of depression from the drone's current location down to its startingpoint? Round your answer to the nearest tenth of a degree. Do not include units in your answer. dyIf x2 - y2 = 1, thendx1(a) yx-1(C) xy-1(b) -xy-(d) - yx When you look at the actions of Republican's and Democrats in Congress; is what they say and,even more importantly, what they do really any different? (essentially, does it really even matterwhich party is in charge?) What structures have parasite worms lost? What structures/organs are expanded? HELP WILL MARK BARINLIEST IF RIGHT!!! simplify please ...... explain what is meant by balance stretching -2a - 7 = -11 (worth 25 points} -2(3x - 10) -what would you get when distributed. For the reaction between aqueous silver nitrate and aqueous sodium chloride, write each of the following. The products of the reaction are aqueous sodium nitrate and solid silver chloride. Complete equationComplete ionic equationNet ionic equation Evaluate: -26 + -17 A large operator of timeshare complexes requires anyone interested in making a purchase to first visit the site of interest. Historical data indicates that 20% of all potential purchasers select a day visit, 50% choose a one-night visit, and 30% opt for a two-night visit. In addition, 30% of day visitors ultimately make a purchase, 10% of one-night visitors buy a unit, and 50% of those visiting for two nights decide to buy. Suppose a visitor is randomly selected and is found to have made a purchase. How likely is it that this person made a day visit Help!Evaluate the logarithmic function for the given value.f(x) = log3 x for f(243)f(243) =M