SOLUTION: Good evening, may I please have help with this problem. I'm stuck. I would use a t-score, but I do not understand how to get the population mean. Thank you in advance. I so appreci

Algebra ->  Probability-and-statistics -> SOLUTION: Good evening, may I please have help with this problem. I'm stuck. I would use a t-score, but I do not understand how to get the population mean. Thank you in advance. I so appreci      Log On


   



Question 1193194: Good evening, may I please have help with this problem. I'm stuck. I would use a t-score, but I do not understand how to get the population mean. Thank you in advance. I so appreciate it.
A nutrition expert claims that the average American is overweight. To test his claim, a random sample of 26 Americans was selected, and the difference between each person's actual weight and idea weight was calculated. For this data, we have x¯=15.3 and s=27.5. Is there sufficient evidence to conclude that the expert's claim is true? Carry out a hypothesis test at a 2% significance level. Hint: Pay attention to the variable being measured: the difference between actual weight and ideal. A positive value indicates that the person is overweight.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
This issue a paired t-test; the variable of interest is the difference from ideal. The mean you will want is the mean difference from ideal weight, and it is +15.3 here
Ho:d=<0
Ha:d>0
alpha=0.02 p{reject Ho|Ho true}
test is a t(0.98, df=25)
critical value t>2.485 one way test
t=(15.3)/27.5/sqrt(26)
=2.84
Reject Ho, there is a significant difference in the mean difference between regular and ideal weight (from 0) in this sample.
p-value =0.0044