Answer:
the mean number of siblings is 8
Step-by-step explanation:
all you have to do is look at the graph.
Sharon would spend $2.50 for the light bulbs she wants.
Answer: 2.28 %
Step-by-step explanation:
Given : Mean : 
Standard deviation :
The formula to calculate the z-score :-

For x = 72

The p-value = 

In percent, 
Hence, the percentage of pediatricians work more than 72 h per week = 2.28 %
Answer:
a = 1 and b = 2
Step-by-step explanation:
Using the Quotient Rule>
d/dx[(sin x)/(2+cos x) ]
= [(2 + cos x) * cosx - sin x * - sin x)] / (2 + cos x)^2
= 2cos x + cos^2x + sin ^2 x) / (2 + cos x)^2
But cos^2x + sin^2x = 1 so we have:
(1 + 2 cos x) / (2 + cos x)^2
- so a = 1 and b = 2.