Exam 3: Descriptive Statistics and Analytics: Numerical Methods

In a hearing test, randomly selected subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the range?

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the mean?

The mean is one component of the five-number summary.

Find the z-score for an IQ test score of 142 when the mean is 100 and the standard deviation is 15.

The arithmetic mean is ________ larger than a weighted mean in a set of data that uses unequal weights.

In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the median?

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the 65th percentile?

Using grouped data of 14 classes with a sample mean of 51 and a sample variance of 6.42, calculate the group sampled standard deviation.

Find the z-score for an IQ test score of 118 when the mean is 100 and the standard deviation is 15.

The average of the squared deviations of the individual population measurement from the population mean is the ________.

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the median?

Researchers wish to study fuel consumption rates based on speed. The data from 10 cars are below. It can be shown that for these data: = 41.9, = 17.8, = 2352.9, = 267.6, ( − ) = −270.2. Calculate the sample correlation coefficient.

The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the 90th percentile?

In a study of the factors that affect success in economics, data were collected for 8 business students. Scores on a calculus placement test are given with economics final exam scores. The data are below: It can be shown that for these data: = 17.75, = 70.38, = 237.50, = 545.875, ( − ) = 140.75. Calculate the sample covariance.

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the first quartile?

The median is the measure of central tendency that divides a population or sample into four equal parts.

A disadvantage of using grouping (a frequency table) with sample data is that

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What are the lower and upper limits of a box-and-whiskers display of this data?

The weights that are used in calculating a weighted mean will vary depending on the situation.

In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the variance?