Given :
A 18-mile taxi ride takes 21 minutes and costs $12.60.
To Find :
The cost of a 39- mile taxi ride. What unit price do you need.
Solution :
Unit price per mile :
Cost of 39 mile taxi ride :
Therefore, unit price is $27.3 and unit price is $0.7 / mile .
Hence, this is the required solution.
Answer: We are 95% confident that the mean SPF level of sunscreen used by all Cal Poly students is between 29.0813 and 40.0187.
Step-by-step explanation:
Given : Significance level :
Sample size : n= 52 , which is a large sample (n>30), so we use z-test.
By using z-value table,
Critical value:
Sample mean :
Standard deviation :
The confidence interval for population means is given by :-
i.e.
Now, the 95% confidence interval for the ppopulation mean = . (29.0813, 40.0187)
Hence, We are 95% confident that the mean SPF level of sunscreen used by all Cal Poly students is between 29.0813 and 40.0187.