Answer:
41 + 2y = 71
2y = 30
y = 15
Step-by-step explanation:
i believe that is right, if not sorry
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.
You need to distribute the numerical factors for each term in the parenthesis:

This equals

179/1018=.17580
.17580*100=17.6%
Answer:
Step-by-step explanation:
this year you earned $75500. Last year you earned $72400. What the rate of change on your earnings since last y?