You have 4 pounds of peanuts. You want to put it in the bags so that there is 2/3 pounds in each bag. How many bags can you fill ?

Null hypothesis:        

Alternative hypothesis:

If we compare the p value and the significance level given we see that so we can conclude that we FAIL reject the null hypothesis, and the the actual sample average lateral recumbency is not significantly lower than 20.        

Step-by-step explanation:

1) Data given and notation        

represent the mean for the sample    

represent the standard deviation for the sample        

sample size        

represent the value that we want to test      

represent the significance level for the hypothesis test.      

t would represent the statistic (variable of interest)        

represent the p value for the test (variable of interest)    

2) State the null and alternative hypotheses.        

We need to conduct a hypothesis in order to determine if the true average lateral recumbency time under these conditions is less than 20 min:      

Null hypothesis:        

Alternative hypothesis:        

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:        

(1)        

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".    

3) Calculate the statistic        

We can replace in formula (1) the info given like this:        

4) Calculate the P-value        

First we need to calculate the degrees of freedom

The critical value for this case would be :

5) Conclusion      

If we compare the p value and the significance level given we see that so we can conclude that we FAIL reject the null hypothesis, and the the actual sample average lateral recumbency is not significantly lower than 20.