Question

A local pizza store knows the mean amount of time it takes them to deliver an order is 45 minutes after the order is placed. The manager has a new system for processing delivery orders, and they want to test if it changes the mean delivery time. They take a sample of delivery orders and find their mean delivery time is 48 minutes and the standard deviation is 10 minutes. Significance level (a=0.05)
Is there any difference of the pizzas delivery time between the sample average and company's claim?

Answer 1

Answer:

We need to conduct a hypothesis in order to check if the true mean is different from 45(alternative hypothesis), and then the system of hypothesis would be:  

Null hypothesis:$\mu =45$  

Alternative hypothesis:$\mu \neq 45$  

Since we don't know the sample size we can't calculate the statistic and the only thing that we can do is create the sytem of hypothesis.

Step-by-step explanation:

Data given and notation  

$\bar X=48$ represent the sample mean    

$s=10$ represent the sample standard deviation

$n$ sample size  

$\mu_o =45$ represent the value that we want to test  

$\alpha=0.05$ represent the significance level for the hypothesis test.  

z would represent the statistic (variable of interest)  

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

System of hypothesis

We need to conduct a hypothesis in order to check if the true mean is different from 45(alternative hypothesis), and then the system of hypothesis would be:  

Null hypothesis:$\mu =45$  

Alternative hypothesis:$\mu \neq 45$  

Since we don't know the sample size we can't calculate the statistic and the only thing that we can do is create the sytem of hypothesis.