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includes prediction of the number of manatees kifled when there are 900,000 boat

ID: 3159801 • Letter: I

Question

includes prediction of the number of manatees kifled when there are 900,000 boats registered in Fiorida Give 95% intervals for (a) the increase in the number of ma:atees die for each additional 1000 boats register (b) the number of manatees that will beated fez? year if there are 900,000 boats registered next yeat. 26.32 Fidgeting keeps you slinm 26.32 Fidgeting keeps you slim: inference. Our first example of regression (Example 5.1, page 128) pre- sented data showing that people who increased their nonexercise activity (NEA) when they were deliber- ately overfed gained less fat than other people. Use software to add formal inference to the data analysis for these data. FATGAIN (a) Based on 16 subjects, the correlation between NEA increase and fat gain was r =-0.7786. Is this significant evidence that people with higher NEA increase gain less fat? (Report a t statistic from regression output and give the one-sided P-value.) (b) The slope of the least-squares regression line was b =-0.00344, so that fat gain decreased by 0.00344 kilogram for each added calorie of NEA. Give a 90% confidence interval for the slope of the population regression line. This rate of change is the most important parameter to be estimated. (c) Sam's NEA increases by 400 calories. His predicted fat gain is 2.13 kilograms. Give a 95% interval for predicting Sam's fat gain. 26. SST Resi 26.33 Predicting tropical storms. Exercise 5.61 (page 160) gives data on William Gray's predictions of the num- ber of named tropical storms in Atlantic hurricane ons from 1984 to 2013. Use these data for regres-

Explanation / Answer

c).

Regression Analysis

0.606

n

16

r

-0.779

k

1

Std. Error

0.740

Dep. Var.

Fat gain (kg)

ANOVA table

Source

SS

df

MS

F

p-value

Regression

11.7941

1  

11.7941

21.55

.0004

Residual

7.6634

14  

0.5474

Total

19.4575

15  

Regression output

confidence interval

variables

coefficients

std. error

   t (df=14)

p-value

95% lower

95% upper

Intercept

3.5051

0.3036

11.545

1.53E-08

2.8539

4.1563

NEA change (cal)

-0.0034

0.0007

-4.642

.0004

-0.0050

-0.0019

Predicted values for: Fat gain (kg)

95% Confidence Interval

95% Prediction Interval

NEA change (cal)

Predicted

lower

upper

lower

upper

Leverage

400

2.1285

1.7142

2.5429

0.4885

3.7686

0.068

95% prediction interval =(0.4885, 3.7686).

Regression Analysis

0.606

n

16

r

-0.779

k

1

Std. Error

0.740

Dep. Var.

Fat gain (kg)

ANOVA table

Source

SS

df

MS

F

p-value

Regression

11.7941

1  

11.7941

21.55

.0004

Residual

7.6634

14  

0.5474

Total

19.4575

15  

Regression output

confidence interval

variables

coefficients

std. error

   t (df=14)

p-value

95% lower

95% upper

Intercept

3.5051

0.3036

11.545

1.53E-08

2.8539

4.1563

NEA change (cal)

-0.0034

0.0007

-4.642

.0004

-0.0050

-0.0019

Predicted values for: Fat gain (kg)

95% Confidence Interval

95% Prediction Interval

NEA change (cal)

Predicted

lower

upper

lower

upper

Leverage

400

2.1285

1.7142

2.5429

0.4885

3.7686

0.068