Answer:

Step-by-step explanation:

Answer:
a = ± 
Step-by-step explanation:
Given
x² = a² - a²w ← factor out a² from each term on the right side
x² = a²(1 - w) ← divide both sides by (1 - w)
= a² ( take the square root of both sides )
±
= a
Answer:
0.7823 = 78.23% probability that the response time is between 3 and 9 minutes.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 7.2 minutes and a standard deviation of 2.1 minutes.
This means that 
For a randomly received emergency call, find the probability that the response time is between 3 and 9 minutes.
This is the pvalue of Z when X = 9 subtracted by the pvalue of Z when X = 3.
X = 9



has a pvalue of 0.8051
X = 3



has a pvalue of 0.0228
0.8051 - 0.0228 = 0.7823
0.7823 = 78.23% probability that the response time is between 3 and 9 minutes.
It is everyone of those except for (-6, 3).
Step-by-step explanation:
4 / 6 = 2/3
2/3 x -9 = -6
2/3 x -12 = -8
2/3 x 3 = 2
2/3 x -6 = -4
18/14, 5/6, and 3/4 would work.