Answer:
Option (b) is correct.
The profit from sales if the price of the T-shirts were $15 a pieces is $28.
Step-by-step explanation:
Given : The function
is used to determine the profit on T-shirts sold for x dollars.
We have to find the profit from sales if the price of the T-shirts were $15 a pieces.
Consider the given profit function 
For the profit, if the price of a t-shirt is $ 15
Put x = 15, we have,

Simplify, we have,

Also, 
Thus, we get, The profit from sales if the price of the T-shirts were $15 a pieces is $28.
Answer:
The standard deviation is used in conjunction with the mean to numerically describe distributions that are bell shaped. The mean measures the center of the distribution, while the standard deviation measures the spread of the distribution.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

The mean is the average value of the measures while the standard deviation measures how spread the measures are from the mean. So
The standard deviation is used in conjunction with the mean to numerically describe distributions that are bell shaped. The mean measures the center of the distribution, while the standard deviation measures the spread of the distribution.
My answer was wrong, I'm am very sorry
16.5/3 = 5.5
Step-by-step explanation:
becuase he needs to walk 16.5 miles. and he can walk 3 miles per x(hour)
you need to devide distance by speed to get time.