Answer:
99.7% of customers have to wait between 8 minutes to 30 minutes for their food.
Step-by-step explanation:
We are given the following in the question:
Mean, μ = 18 minutes
Standard Deviation, σ = 4 minutes
We are given that the distribution of amount of time is a bell shaped distribution that is a normal distribution.
Empirical Formula:
- Almost all the data lies within three standard deviation from the mean for a normally distributed data.
- About 68% of data lies within one standard deviation from the mean.
- About 95% of data lies within two standard deviations of the mean.
- About 99.7% of data lies within three standard deviation of the mean.
Thus, 99.7% of the customers have to wait:

Thus, 99.7% of customers have to wait between 8 minutes to 30 minutes for their food.
You mean a square has an AREA of 100 square meters?
The length of 1 side equals square root of 100 = 10 meters.
Therefore perimeter = 4 * 10 = 40 meters.
A. 4x - 3 = 2x + 7
4x - 2x = 7 + 3
2x = 10
x = 5
B. 2x + 6 = 7x - 14
2x - 7x = - 14 - 6
-5x = -20
x = 4
C. 2( x + 3) = x - 4
2x + 6 = x - 4
2x - x = -4 - 6
x = -10
D.4 ( 5x - 2) = 2( 9x + 3)
20x - 8 = 18x + 6
20x - 18x = 6 + 8
2x = 14
x = 7
E.4x - 1/2 = x - 7
4x - x = -7 + 1/2
3x = (-14 + 1)/2
3x = -13/2
x = -13/6
F. 3x + 2 = 2x + 13/3
3x - 2x = 13/3 - 2
x = (13 - 6)/3
x = 7/3
Hope This Helps You!