Silva set up a dog-walking business. He earned $60 in June. He is projected to earn 110% more in July. How much is Silva project
1 answer:
You might be interested in
Answer: D)
Step-by-step explanation:
As per given , we have
Sample size : n= 15
sample mean :
Sample standard deviation: s= $20
Since population standard deviation is unknown , so we use t-test.
Significance level for 95% confidence :
Critical t-value : [Using students' t-value table]
Required 95% Confidence interval :-
Hence, the required 95% confidence interval for the mean amount its credit card customers spent on their first visit to the chain's new store in the mall assuming that the amount spent follows a normal distribution.: