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.:
Answer:
Step-by-step explanation:
Let consider that door has a height of 5 feet and a width of 3 feet. The scale factor is:
The height of the cabinet is:
we have 
which is a cubic function.
and 
.
from f(x) and g(x) we know that both are cubic and g(x) has shrink of 1 and up by 4 units in x axis .
It is important to note that all the information's required are already given in the question
Probability that a day will be hot = 0.15 + 0.10
= 0.25
Probability that a day will be sunny = 0.15 + 0.30 + 0.10
= 0.55
Adding the above two probabilities, we get = 0.25 + 0.55
= 0.80
Now
Probability that a day will be both hot and sunny = 0.15
So
Probability that a day was hot or sunny = 0.80 - 0.15
= 0.65
I hope the procedure is clear enough for you to understand.
