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In a study designed to test the \"truth\" to the theory that, on average, U.S. a

ID: 3179265 • Letter: I

Question

In a study designed to test the "truth" to the theory that, on average, U.S. adults gain weight between Thanksgiving and January a research team looked at responses from 8 randomly selected U.S. adults. The subjects were weighed (lb) on the day before Thanksgiving and again on January 3rd The raw data are found in Table 1. Let = 0.02


A) Fill in the missing table cells for the weight differences per the directions outlined in the bottom caption.

B) The point estimate for the true average weight gain that U.S. adults have from Thanksgiving until Jan. 3 is a:        point  ---Select---  increase decrease no effect
    Note: round your answer for the first part of this question to 3 decimal precision

C) The point estimate for the true standard deviation of the weight gain that U.S. adults have from Thanksgiving until Jan. 3 is:  
     Note: round your answer to 3 decimal precision

D) The appropriate null/alternative hypothesis pair for this study is:

Ho: xd 0 ; Ha: xd < 0

Ho: = 0 ; Ha: 0   

Ho: d = 0 ; Ha: d 0

Ho: d 0; Ha: d 0

Ho: d 0 ; Ha: d > 0

Ho: < 0 ; Ha: 0

Ho: d < 0 ; Ha: d 0

Ho: 0 ; Ha: < 0

Ho: d > 0 ; Ha: d < 0

Ho: d < 0 ; Ha: d > 0

Ho: d = 0 ; Ha: d > 0

Ho: xd 0 ; Ha: xd > 0



E) The test statistic for this data set is:  
     Note: Round your answer to the nearest hundredth.

F) The P-value for this study is:  
     Note: round your answer to 4 decimal precision

G) Based on this we:

FTR Ho because the p-value is greater than the significance level

Reject Ha because the p-value is greater than the significance level    

Reject Ho because the p-value is greater than the significance level

FTR Ha because the p-value is greater than the significance level

Table 1: Weights (lb) before Thanksgiving and on Jan. 3rd for 8 U.S. adults Pre-Thanksgiving 148.8 149.1 149.9 149.7 149.8 151.3 146.6 145.1 Jan. 3rd 150.1 150.6 152.5 150.7 147.9 150.1 151.7 151.4 Diff Since the researchers believe that adults, on average, gain weight you should compute the differences as Jan. 3 - PreThanksgiving and expect positive numbers.

Explanation / Answer

from above data

a) data in differnce column

b) point estimate for the true average weight gain 1.838 increase

c)The point estimate for the true standard deviation of the weight gain=2.814

d)Ho: d 0 ; Ha: d > 0

e)The test statistic for this data set is: =d/std error =1.85

f) The P-value for this study is: =0.0510

g)FTR Ho because the p-value is greater than the significance level

pre Jan 3rd difference(d) 148.8 150.1 1.3 149.1 150.6 1.5 149.9 152.5 2.6 149.7 150.7 1 149.8 147.9 -1.9 151.3 150.1 -1.2 146.6 151.7 5.1 145.1 151.4 6.3 mean 1.838 std deviaition 2.8142 std error= std dev/(n)^(1/2) 0.9950 t stat= (d-0)/std error 1.8468