Marcus hired a car service to drive him to the airport. The bill came to $56.80. He gave the driver a 20% tip. How much money di
2 answers:
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Answer: (30.49 years, 42.31 years)
Step-by-step explanation:
The formula to find the confidence interval is given by :-
, where = Sample mean
z* = Critical value.
= Population standard deviation.
n= Sample size.
As per given , we have
n= 40
We know that the critical value for 99% confidence interval : z* = 2.576 (By z-table)
A 99 percent confidence interval for µ, the true mean age of guests will be :
∴ a 99 percent confidence interval for µ, the true mean age of guests = (30.49 years, 42.31 years)
Answer: The critical value for a two-tailed t-test = 2.056
The critical value for a one-tailed t-test = 1.706
Step-by-step explanation:
Given : Degree of freedom : df= 26
Significance level :
Using student's t distribution table , the critical value for a two-tailed t-test will be :-
The critical value for a two-tailed t-test = 2.056
Again, Using student's t distribution table , the critical value for a one-tailed t-test will be :-
The critical value for a one-tailed t-test = 1.706
