6, 7, 8, and 9. just plug the X into the equation
Answer:
q = -15
Step-by-step explanation:
5q = -75
Divide both sides by 5 : q = -15
Answer:
For the 99th percentile, we have X = 206 seconds.
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 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 pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

99th percentile:
Value of X when Z has a pvalue of 0.99. So we use 




For the 99th percentile, we have X = 206 seconds.