/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q. 11 Growth hormones are often used t... [FREE SOLUTION] | 91影视

91影视

Growth hormones are often used to increase the weight gain of chickens. In an experiment using 15chickens, five different doses of growth hormone (0, 0.2, 0.4, 0.8, and 1.0milligrams) were injected into chickens (3chickens were randomly assigned to each dose), and the subsequent weight gain (in ounces) was recorded. A researcher plots the data and finds that a linear relationship appears to hold. Computer output from a least-squares regression analysis for these data is shown below.

role="math" localid="1652870715985" PredictorCoefSE CoefTPConstant4.54590.61667.37<0.0001Dose4.83231.01644.750.0004S=3.135R-Sq=38.4%R-Sq(adj)=37.7%

(a) What is the equation of the least-squares regression line for these data? Define any variables you use.

(b) Interpret each of the following in context:

(i) The slope

(ii) The yintercept

(iii) s

(iv) The standard error of the slope

(v) r2

(c) Assume that the conditions for performing inference about the slope B of the true regression line are met. Do the data provide convincing evidence of a linear relationship between dose and weight gain? Carry out a significance test at the A =0.05level.

(d) Construct and interpret a 95%confidence interval for the slope parameter.

Short Answer

Expert verified

(a) The equation of the least-squares regression line isy^=4.5459+4.8323x.

(b) The values are

(i) b=4

(ii) a=4.5450

(iii) s=3.135

(iv) SEb=1.0164

(v)role="math" localid="1652871593895" r2=38.4%

(c) There's sufficient convincing evidence to justify the argument.

(d) There is a 95%chance that the weight gain will be between 2.636876and 7.027724. While the does, the ounces climb by 1milligram.

Step by step solution

01

Part(a) Step 1: Given Information

PredictorCoefSE CoefTPConstant4.54590.61667.37<0.0001Dose4.83231.01644.750.0004S=3.135R-Sq=38.4%R-Sq(adj)=37.7%

02

Part(a) Step 2: Explanation

a=4.5459

b=4.8323

The general regression line equation

y^=a+bx

By inserting values the regression line becomes:

role="math" localid="1652870965008" y^=4.5459+4.8323x

With xDose and yweight gain.

03

Part(b) Step 1: Given Information

PredictorCoefSE CoefTPConstant4.54590.61667.37<0.0001Dose4.83231.01644.750.0004S=3.135R-Sq=38.4%R-Sq(adj)=37.7%

04

Part(b) Step 2: Explanation

(i) b=4is the first output. The weight per milligram might increase by 4.8323ounces.

(ii). In the result a=4.5450, the y-intercept is mentioned.

This means that the weight will be 4.5459ounces if the dosage is 0milligrams.

(iii) s=3.135is the output. This means that the average prediction error is 3.1350ounces.

(iv) SEb=1.0164This suggests that the population's true slope is 1.016-1on average over all feasible samples.

(v)r2is written asr2=R-Sq=38.4%. This means that the least-square regression line explains 38.4%of the variance in the variables.

05

Part(c) Step 1: Given Information

PredictorCoefSE CoefTPConstant4.54590.61667.37<0.0001Dose4.83231.01644.750.0004S=3.135R-Sq=38.4%R-Sq(adj)=37.7%

06

Part(c) Step 2: Explanation

Define hypothesis

H0:=0

H1:0

The test statistic is

t=b-0SEb=4.8323-01.0164=4.754

The P-value is the probability of having the test numbers' value or a more dramatic value. The t-value in the rowrole="math" localid="1652872078633" df=n-2=15-2=13 is represented by a number (or interval) in Table B column title:

P<0.0005

The null hypothesis is rejected if the p-value is less than or equal to the degree of significance.

P<0.05RejectH0

07

Part(d) Step 1: Given Information

PredictorCoefSE CoefTPConstant4.54590.61667.37<0.0001Dose4.83231.01644.750.0004S=3.135R-Sq=38.4%R-Sq(adj)=37.7%

08

Part(d) Step 2: Explanation

Degrees of freedom

df=n-2=15-2=13

Table B, in the row of df=13and the column of c=95%, has the important t-value.

The essential t-value may be found in table B in the c=95%column and in the df=13row.

t*=2.160

The boundaries are

role="math" localid="1652872255479" b-t*SEb=4.8323-2.1601.0164=2.636876

b+t*SEb=4.8323+2.1601.0164=7.027724

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

In physics class, the intensity of a 100-watt light bulb was measured by a sensor at various distances from the light source. A scatterplot of the data is shown below. Note that a candela (cd) is a unit of luminous intensity in the International System of Unit

Physics textbooks suggest that the relationship between light intensity y and distance x should follow an 鈥渋nverse square law,鈥 that is, a power-law model of the form y=ax-2. We transformed the distance measurements by squaring them and then taking their reciprocals. Some computer output and a residual plot from a least-squares regression analysis on the transformed data are shown below. Note that the horizontal axis on the residual plot displays predicted light intensity

(a) Did this transformation achieve linearity? Give appropriate evidence to justify your answer.

(b) What would you predict for the intensity of a 100-watt bulb at a distance of 2.1meters? Show your work.

Following the debut of the new SAT Writing test in March 2005, Dr. Les Perelman from the Massachusetts Institute of Technology collected data from a set of sample essays provided by the College Board. A least-squares regression analysis was performed on these data. The two graphs below display the results of that analysis. Explain why the conditions for performing inference are not met in this setting.

Insurance adjusters are always vigilant about being overcharged for accident repairs. The adjusters suspect that Repair Shop 1quotes higher estimates than Repair Shop 2. To check their suspicion,

the adjusters randomly select 12cars that were recently involved in an accident and then take each of the cars to both repair shops to obtain separate estimates of the cost to 铿亁 the vehicle. The

estimates are given below in hundreds of dollars.


Assuming that the conditions for inference are reasonably met, which of the following signi铿乧ance tests could legitimately be used to determine whether the adjusters鈥 suspicion is correct?

I. A paired ttest

II. A two-sample ttest

III. A t test to see if the slope of the population regression line is 0.

(a) I only

(b) II only

(c) I and III

(d) II and III

(e) I, II, and III

A distribution of exam scores has mean 60and standard deviation 18. If each score is doubled, and then 5is subtracted from that result, what will be the mean and standard deviation, respectively, of the new scores?

(a) mean=115and standard deviation=31

(b) mean=115and standard deviation=36

(c) mean=120and standard deviation=6

(d) mean=120and standard deviation=31

(e) mean=120 and standard deviation=36

Prey attracts predators Refer to Exercise 3. Computer output from the least-squares regression analysis on the perch data is shown below.

The model for regression inference has three parameters: ,and . Explain what each parameter represents in context. Then provide an estimate for each.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.