Answer:
a. 8.66 minutes
Step-by-step explanation:
Since the flight times are uniformly distributed, the standard deviation can be calculated as follows:
Where '<em>b' </em>is the maximum flight time (150 minutes) and '<em>a' </em>is the minimum flight time (120 minutes):
The distribution's standard deviation is 8.66 minutes.
Answer:
The 90% confidence interval is (0.1897, 0.2285).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence interval
, we have the following confidence interval of proportions.
In which
Z is the zscore that has a pvalue of
For this problem, we have that:
From a July 2019 survey of 1186 randomly selected Americans ages 18-29, it was discovered that 248 of them vaped (used an e-cigarette) in the past week. This means that
Construct a 90% confidence interval to estimate the population proportion of Americans age 18-29 who vaped in the past week.
So , z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:
The upper limit of this interval is:
The 90% confidence interval is (0.1897, 0.2285).