Statistics for Business
Find the zz-score that corresponds to the following percentile:
P2.5\(\text{P}\)2.5
In a survey of weekly hours spent on online courses by a group of students, the following hours were reported: 55, 88, 1010, 1212, 1515, 77, 99, 1111, 66, 88, 1010, and 77. Calculate the zz-score for the student who spent the most hours online.
Determine the probability that a standard normal variable ZZ is less than −0.52-0.52.
The heights of adult male giraffes in a wildlife reserve are bell-shaped with a mean of 17.217.2 feet and a standard deviation of 1.11.1 feet. A particular giraffe is measured at 14.714.7 feet. Calculate the zz-score for this giraffe's height and determine if it is unusual.
The figure below shows the continuous uniform distribution of customer waiting times at a coffee shop. Determine the mean and standard deviation for the distribution of the waiting times.
If a problem asks for the probability that z is less than a certain value, which tail is being referenced?
A TI-84 Plus (not CE) only accepts left-tail areas. You are given P(z > b) = 0.30. What area should you input to find z?
The distribution of ages for marathon winners in a certain city is approximately bell-shaped, with a mean of 32.532.5 years and a standard deviation of 4.24.2 years. In 20122012, the winner was 4343 years old. Find the zz-score for this age and state whether it is unusual.
What are the mean and standard deviation of the standard normal distribution?
In a survey of 180180 employees, the highest monthly salary recorded was $7,200\$7,200. The mean monthly salary was $5,400\$5,400 with a standard deviation of $600\$600. What is the zz-score for the highest salary? Express your answer with two decimal places.