The probability of
is
.
Further Explanation:
The Z score of the standard normal distribution can be obtained as,

Here, Z is the standard normal value,
represents the mean,
represents the standard deviation.
Given:
The mean of test is
.
The standard deviation of the waiting time is
.
Explanation:
The probability of mean lies between 55.5 to 69.7 can be calculated as follows,

Further solve the above equation to obtain the probability.

The probability of
.
The probability
.
The probability can be calculated as follows.

Hence, the probability of
is
.
Learn more:
1. Learn more about normal distribution <u>brainly.com/question/12698949</u>
2. Learn more about standard normal distribution <u>brainly.com/question/13006989</u>
3. Learn more about confidence interval of mean <u>brainly.com/question/12986589</u>
Answer details:
Grade: College
Subject: Statistics
Chapter: Confidence Interval
Keywords: Z-score, Z-value, binomial distribution, standard normal distribution, standard deviation, test, measure, probability, low score, mean, repeating, indicated, normal distribution, percentile, percentage, proportion, empirical rule.