Question

Q1. Does an average box of cereal contain 368 grams of cereal? A random sample of 36 boxes had a mean of 372.5 and a standard deviation of 12 grams. Test at the .05 level of significance.

Answer 1

Null hypothesis  

              
                  
Alternative hypothesis      

          
                  
We have for given sample,                  
Population mean for given sample=368  
Sample mean=372.5          
Sample standard deviation s=12      
Sample size =n=   36          
                  
Degree of freedom = n-1 =35      
                  
                  
                  
t test statistic formula is                  

P value = 0.0308................by using Excel command TDIST(2.25,35,2)

P value is = 0.0308 < 0.05

Therefore, we reject H0 at