Answer: 
Step-by-step explanation:
Given : Sample size : 
Sample mean : 
Standard deviation : 
Significance level : 
Critical value : 
Formula to find the confidence interval for population mean :-

Hence, a 90% confidence interval estimate of the population mean of all students = 
Answer:
Do 16 times pi.
Step-by-step explanation:
The closest answer is D.
Answer:
m = $14/day
w = $6/day
Step-by-step explanation:
See attached image.
19. (X+5)-3
20. 2a
21.3b
22. 5y-5
23. 1/2n-15
Answer:
The correct answer is A.
Step-by-step explanation:
face value = 1.86 , charges are 20% more for smokers
⇒ Charges = 20% of 250000 = $50000
Total charge = Charge × face value
= 50000 × 1.86 = $93000
face value = 1.86 , charges are 18% more for smokers
⇒ Charges = 18% of 250000 = $45000
Total charge = Charge × face value
= 45000 × 1.86 = $83700
face value = 2.07 , charges are 25% more for smokers
⇒ Charges = 25% of 250000 = $62500
Total charge = Charge × face value
= 62500 × 2.07 = $129375
face value = 2.25 , charges are 15% more for smokers
⇒ Charges = 15% of 250000 = $37500
Total charge = Charge × face value
= 37500 × 2.25 = $84375
Hence, The option A. is correct that is Aaron is paying the smallest premium possible with company B