A shoe company wants to test an updated model of a running shoe on its wear after one month of running. They recruit 50 people who run on a regular basis to participate in the study. Twenty-five runners will receive a pair of the new model and the remaining 25 will receive a pair of the current model. After one month, the wear on the shoes will be determined using the depth of the tread and the flexibility of the toe box. The wear between the new and current models will then be compared.

Which of the following describes a completely randomized design for this experiment?

The subjects are numbered 1–50 and these numbers are put into a random number generator. The first 25 random numbers, ignoring repeats, represent the subjects assigned to the new model group. The remaining 25 subjects will wear the current model.
The subjects’ names are written on equal-sized slips of paper and placed into a hat. A researcher then reaches in and pulls out 25 slips of paper. These subjects are assigned to the new model group. The remaining 25 subjects will be assigned to the current model group.
The 50 subjects are paired based on running ability. The fastest two runners are paired together, the next fastest, etc. For each pair of runners, the researcher will flip a coin. If the coin lands on heads, the first runner will receive the new model and the second runner will receive the original model.
The 50 subjects are grouped based on running ability. Twenty runners classify themselves as competitive runners and the remaining 30 classify themselves as recreational runners. For the competitive group, the runners’ names are written on equal-sized slips of paper and placed into a hat. The slips are shuffled, and the first 10 runners wear the new model and the other 10 wear the current model. The same procedure is used to assign the shoes to the recreational group.

Answers

Answer 1

Answer:

Option A: The subjects are numbered 1–50 and these numbers are put into a random number generator. The first 25 random numbers, ignoring repeats, represent the subjects assigned to the new model group. The remaining 25 subjects will wear the current model.

Step-by-step explanation:

We are told that Twenty - five runners will receive a pair of the new model and the remaining 25 will receive a pair of the current model.

Now, a completely randomized design is defined as one where the treatments will be assigned completely at random in such a manner that each experimental unit will posses the same chance of receiving any of the treatments given.

To this effect, the most likely answer will be picking people at random to assign either the new model or current model.

This is usually done by making a list of the treatment combinations and then assigning a random number to each subject.

Looking at the options, the most appropriate will be option A.


Related Questions

HELPPPPPP!!!!!!!!!!!!!

Answers

Answer:

Statement F is true

Step-by-step explanation:

Let x represent number of yoga classes

Let y represent total cost

Let m represent the additional fee per yoga class

Let b represent the membership fee

y=mx+b

Notice that after every 2 classes, the price goes up by 7.5 so m=7.5/2

m=3.75

Thus the first statement is true

Note you can also find the membership fee if you plug this in with some points

y=mx+b

67.5=3.75(6)+b

b=45 so membership fee is $45


I need help with this question can anyone help ?

Answers

Answer:

m < 1 = 72

Step-by-step explanation:

Since we know that line l and line m are parallel and that p is one of their transversals, it sets up a situation where we can identify which angles are congruent (equal) to one another according to their positions.

In this case, we can see that < 3 and < 1 are in the same matching corners created by the transversal. When angles are in the same matching corners they are called corresponding angles - and according to the Corresponding Angles Postulate, corresponding angles are congruent.

Therefore, m < 3 = m < 1, and since it's given that  m < 3 = 72, we know that m < 1 = 72 too.

Which relation is a function?
OA.
{(2, 3), (1, 5), (2, 7))
B. (-1, 5), (-2, 6), (-3, 7)
Oc. (11,9), (11, 5), (9, 3))
OD.
(3, 8), (0, 8), (3, -2)}

Answers

It’s B because the domain(x) doesn’t repeat like the other options.

Twice a number is 42 less then five times a number. What is the number? Define a variable, write an equation, and then solve.

Answers

Answer:

Given - Twice a no. is 42 less than 5 times a no.

To find - The no.

Solution -

Let the no. be X

According to the question the equation made is -

2x = 5x - 42

2x - 5x = (-42)

(-3x) = (-42)

x= (-42)/(-3)

x = 14

The no. is 14

Really need help !!!!!!!!

Answers

With what? You didn’t put a picture lol

Aleena expands 2xx+3-5(x-2) as 2x2+3-5x-10. Has she expanded it correctly? Please identify the mistakes and write the correct way in which 2xx+3-5(x-2) should be expanded.

Answers

The given expression is :

2xx+3-5(x-2)

We know that, [tex]x{\cdot}x=x^2[/tex]

[tex]=2x^2+3-5(x-2)\\\\=2x^2+3+(-5)(x)+(-5)(-2)\\\\=2x^2+3-5x+10[/tex]

Aleena expands 2xx+3-5(x-2) as 2x²+3-5x-10. She is mistaken because the sign before 10 should be +10 instead of -10. Hence, the correct expanded form is 2x²+3-5x+10. Hence, this is the required solution.

Help plz I don’t have much time

Answers

Answer:

nine and two fifths(  9 2/5 )

Step-by-step explanation:

i used a fraction calclulator

Answer:9.4

Step-by-step explanation:

Finding Angles By Deg
Determine if the angle described is 'acute', 'obtuse',
1) 180°
2) 46°
3) 53°

Answers

Answer:

1) Obtuse

2) Acute

3) Acute

Step-by-step explanation:

Anything under 90 degrees is an Acute angle, while anything above is an Obtuse. A 90 degree angle is a right angle.

Please Brainiest!

Evaluate -3x^3 - 4x for x=-1.

Answers

Answer:

-x.(3x^2+4)

Step-by-step explanation:

Brain-list?

Answer:

-3(-1)^3-4(-1)= 27+4=31

Step-by-step explanation:-3 and -1 when you multiply both minus will change into plus. same for -4 and -1 when you multiply will change the signs. so you will get 27+4=31

which value if x makes this proportional true? 14/20=56/x A.x=62 B.x=70 C.x=80 D.x=100​

Answers

Answer:  C) x = 80

==================================================

Work Shown:

Let's cross multiply to get the following

14/20 = 56/x

14*x = 20*56

14x = 1120

x = 1120/14

x = 80

-------------------

As a way to check the answer, we can type 14/20 - 56/80 into the calculator and we should get 0. I'm taking advantage of the rule that if A = B, then A-B = 0. This trick is handy to check if two sides of any equation are equal to one another.

your answer will be 80 pretty sure

Evaluate.
0^2=
I do not get this way toooooooo hard

Answers

Answer:

zero

Step-by-step explanation:

Answer:The answer is 0

Step-by-step explanation: Sorry i didn't explain it.

Which is the graph of arctan(x)?

Answers

Answer:

The Inverse Tangent Function (arctan)

Graph of y = tan x.

The graph of arctan(x) is second graph.

We have inverse function [tex]y=tan^{-1} x[/tex]

Creating the table

x     0   π/4    π/2     -π/2     -π/3      π/3

y     0   1         ∞        -∞       -√3       √3

From the given graphs we see that the second graph satisfies the values.

So, the correct graph for arctan(x) is second graph.

Learn more:https://brainly.com/question/2849972

how many meters an Ostrich can run in 1 second, 2 seconds , and 4 seconds?

Answers

Answer:

An ostrich could run near 21 meters in 2 seconds and around 84 meters in 4 seconds

Heather drives 130 miles in 2 hours. If she travels the same distance each hour, how many miles does she drive per hour?​

Answers

Answer:

she drive 65 miles Per hour

Answer:

if she drive for two more hours that means she drove 4 hours and plus 130 plus 130 and that will equal 260. so the answeris 260.

Step-by-step explanation:

how to find x of the (x+95) and (4x-10)

Answers

Answer:

x=35

Step-by-step explanation:

x+95=4x-10

Subtract x on both sides

95=3x-10

Add x on both sides

105 = 3x

x=35

Hope this helps plz hit the crown :D

Answer:

x = 35

Step-by-step explanation:

(x + 95) = (4x - 10)             get rid of the parentheses

x + 95 = 4x - 10                 put the x's together and put your constants together

105 = 3x                            divide 3 from both sides

35 = x

Hope this helps

A real estate software program gives the estimated values of homes and lists characteristics of the homes. A prospective home buyer used the program to collect a sample of twenty-five homes and recorded the estimated value of the homes and how many bathrooms they contain. The prospective home buyer wants to investigate whether there is an association between the number of bathrooms a home contains and the estimated value of the home. Assuming all conditions for inference are met, which of the following significance tests should be used for the investigation?A. A two-sample z-test for a difference between proportionsB. A linear regression t-test for slopeC. A matched pairs t-test for a mean differenceD. A two-sample t-test for a difference between meansE. A chi-square test of independence

Answers

Answer:

E - Chi-Square Test of Independence

Step-by-step explanation:

- The Two-Sample Z-test is used to compare the mean of two samples in order to find out the possibility that they come from the same population.

-A linear regression t-test for slope is used to carry out hypothesis tests on the regression coefficients which are obtained in simple linear regression.

-A matched-pairs t-test is used to test whether there is a significant difference in mean between two sets of paired data.

- A two sample t-test is used to test whether the unknown population mean found in two groups are either equal or not equal.

-Chi-Square Test of Independence is a non-parametric test that is used to find out whether there is an association between categorical variables. Simply put, to find out if the categorical variables are independent or related.

From the question, the prospective home buyer is trying to investigate whether there is an association between the two variables which are the number of bathrooms contained in home and the estimated value of the home.

This means he is trying to find out if both variables are associated i.e.either independent or related. This is what Chi-Square Test of Independence does.

Answer:

A chi-square test of independence

Step-by-step explanation:

colllege board

In a right triangle, the tangent of angle A is 9/12 and the cosine of angle a is 12/15 based on these values what is the sine of angle a

a. 9/15
b 15/16
c 1, 1/15
d 1. 11/20

Answers

Answer:

option A 9/15

im srry i suck at math

30 points On a certain hole, a golfer knows that he has a 70% chance of reaching the green (putting surface) in one stroke, 20% in two strokes, 8% in three, and 2% in four or more. If he reaches the green on his first stroke, he has an 80% chance of putting the golf ball in the cup on his second stroke. If he does not reach the green on his first stroke, then he has a 30% chance of putting the golf ball in the cup on his second stroke. What is the probability that the golfer will reach the green in one stroke and put the ball in the cup on his second stroke?

0.09
0.21
0.56
0.80

Answers

0.56 i might be wrong tho

Answer:

.56

Step-by-step explanation:

Solve for x 1000 = 500e^2x
Can someone help me please

Answers

Answer: A

Step-by-step explanation:

1000 = 500e^(2x)

2 = e^(2x)

ln2 = 2x

Step-by-step explanation:

1000 = 500e^(2x)

2 = e^(2x)

ln2 = 2x

x = ln2 / 2. (A)

What is the value of y = cos (θ) when θ = π?

Answers

Answer:

The cosine function forms a wave that starts from the point (0,1) cos θ = 0 when θ = 90˚, 270˚. Maximum value of cos θ is 1 when θ = 0˚, 360˚.

Step-by-step explanation:

9. A machine can make 32 water bottle every 6 minutes. At this rate, how many water bottles can the machine make in 60 minutes? A 92 B 38 с 326 D 320 1​

Answers

Answer:

320

Step-by-step explanation:

32 bottles  in 6 minutes add a 0 so you get 320 bottles in 60 minuts.

Answer:

D 320

Step-by-step explanation:

Since 60 minutes is 10 times 6 minutes, the machine can make 10 time more water bottles in 60 minutes than it can make is 6 minutes.

10 * 32 = 320

Answer: D 320

You can also solve by using a proportion.

32/6 = x/60

6x = 60 * 32

Divide both sides by 6.

x = 10 * 32

x = 320

Answer: D 320

8. Iris wants to buy two necklaces, one for her sister and one for herself. The necklace for her sister costs $42.00, and the necklace for herself costs $28.00. The sales tax on the purchases is 8%. Find the total cost of Iris's purchases, including sales tax. If necessary, round your answer to the nearest cent. C $75.60 A $64.40 B $5.60 B D $70.00​

Answers

the answer is C!
Hope this helps

Which point is located in Quadrant I?
(shown in pic)


Don’t answer if you don’t know, but if get it right i’ll give brainiest! it’s due soon pls help.

Answers

The point in quadrant one is C

Answer:

c

the top right is quadrant l, the top left is quadrant ll, the bottom left is quadrant lll, and the bottom right is quadrant lV

(8m-2)(3m+7)
Multiply

Answers

Answer:

24m^2+50m-14

Step-by-step explanation:

A June 2009 Harris Interactive poll asked people their opinions about the influence of advertising on the products they buy. Among the people aged 18 to 34 years, 45% view advertisements as being influential, whereas among the people aged 35 to 44 years, 37% view advertisements as being influential. Suppose that this survey included 655 people in the 18- to 34-year age group and 420 in the 35- to 44- year age group. At the 1% significance level, can you conclude that the proportion of all people aged 18 to 34 years who view advertisements as being influential in their purchases is greater than the proportion of all people aged 35 to 44 years who hold the same opinion

Answers

Answer:

We accept with 99 % of confidence that p₁ ( the proportion in the group aged 18 - 34 ) is bigger than p₂ (the proportion in the group aged 35-44)

Step-by-step explanation:

Group aged  18 - 34

Sample size n₁  =  655  sample size enough to apply a normal distribution aproximation for the test

p₁ = 0,45      and   q₁ =  1 - p₁      q₁ = 0,55

p₁*n₁  =  0,45*655 = 294     q₁*n₁  = 0,55*655 = 360

both bigger than 5

p₁  = 45 %     or     p₁  = 0,45          then  q₁  = 1 - 0,45    q₁ = 0,55

Group aged 35 - 44

Sample size  n₂  =  420 sample size enough to apply a normal distribution aproximation for the test

p₂  =  37%   p₂ = 0,37     and    q₂  = 0,63

p₂*n₂  =  0, 37*420 =  155     q₁*n₁  = 0,63*420 = 264

Test Hypothesis

Null Hypothesis        H₀                                             p₁  =  p₂

Alternative Hypothesis Hₐ                                        p₁  >  p₂

Significance level    α  =  1%   α  = 0,01

Confidence Interval     CI = 99 %

Then   from z table  we find   critical z   z (c )  = 3,1

Calculating   z(s)

z(s)  =  (  p₁ - p₂ )/ √[ ( p₁*q₁)/n₁ ] + [ (p₂*q₂)/n₂ ]

z(s ) = (0,45 - 0,37 ) /  √ 0,45*0,55)/655  +  0,37*0,63 /420

z(s)  = 0,08  /0,03

z(s) = 2,66

Comparing  z(s)  and z(c)

z(s) < z(c)

Then z (s) is inside the acceptance region for H₀

from first principle find the derivative of logx​

Answers

Hello!

[tex]\large\boxed{\frac{dy}{dx}logx = \frac{1}{xln10} }[/tex]

Recall that:

[tex]logx[/tex] can be rewritten as:

[tex]log_{10}x[/tex]

Use the equation for the derivative of a log expression:

[tex]\frac{dy}{dx}log_{a}u = \frac{1}{ulna} * u'[/tex]

Substitute in the values in the expression:

[tex]logx = \frac{1}{xln10} * 1 = \frac{1}{xln10}[/tex]

To make lemonade, Brandon mixes 9 cups of water with 2 cans of frozen lemonade concentrate.

Answers

Answer:

Step-by-step explanation:

Y la pregunta?

2/3y + 1/6y =

Please help me, I am unsure about this one. I just need a grasp on where to start.

Answers

The answer is 5/6y when you add both together
You can double 2/3 since the common denominator for 2/3 and 1/6 is 6 and you have 4/6y+1/6y which equals 5/6y

Is the function f(x) = 3(.96)x an exponential growth or exponential
decay function? Why?

Answers

Answer:

exponential decay

Step-by-step explanation:

anything less than 1 in the parenthesis is decay

Susan and Jim each own a lawn-care business. The amount Susan charges for lawn care by the hour is shown in the table. The amount Jim charges for lawn care by the hour is shown in the graph.

Answers

Answer:

Can you please provide the table so I can know the numbers.

Step-by-step explanation:

Thank you

Answer:

plss stop english plss lang po

he

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