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.:

Let the youngest sister be n years
Lana will be 2n years, as her youngest sister is half her age
The age of the twins separately will be 2n-2 as they are 2 years younger than Lana
So, the equation looks like this:
n + 2n + 2(2n-2) = 45
Now solve for n:
3n + 4n - 4 = 45
7n - 4 = 45
7n = 49
n = 7
So the youngest sister is 7, Lana is 14 and the twins are 12. 14 + 12 + 12 + 7 =45
I wanna say 32 because it repeats it in the question
Answer:
2:1 that is 2 inches in real life is equal to 1 inch in the drawing.
Step-by-step explanation:
We are given the following in the question:
Longest side of the pool = 10 inches
Longest side of the pool in drawing = 5 inches
Scale:
We find the ratio of the real length of pool and the measurement of the length of the pool in the drawing.

Thus, we can say Paco's new drawing follows a scale of 2:1 that is 2 inches in real life is equal to 1 inch in the drawing.