Exam 3: Descriptive Statistics: Numerical Methods

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;mean = 114.15): 118,124,108,116,99,120,148,118,119,121,45,130,118. What is the variance?

The line that minimizes the sum of the squared horizontal (x)distances between the points on the scatter plot and the line is the least squares line.

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 IQR?

When using Chebyshev's Theorem to obtain the bounds for 99.73 percent of the values in a population,the interval generally will be ___________ the interval obtained for the same percentage if a normal distribution is assumed (Empirical Rule).

In a hearing test,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 variance?

Using Chebyshev's Theorem,approximate the minimum proportion of the data that will be within μ ± kσ for k = 3.2.

The population variance is the average of the squared deviations of the individual population measurements from the population mean.

Using Chebyshev's Theorem,find the interval that contains at least 93.75 percent of all measurements when the mean = 2.549 and s = 1.828.

A random sample of 60 students in the business statistics course answered a survey on the average number of hours they spent on statistics each week.Unfortunately,the original data were lost and all that remains is the frequency table below.From these data,calculate the estimated sample standard deviation.

A quantity that measures the variation of a population or a sample relative to its mean is called the ____________.

In the calculation of a mean for grouped data,we assume that the average of the measurements in each class equals the class midpoint.

The median is said to be resistant to extreme values.

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 first quartile?

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: 140.75. Calculate the sample correlation coefficient.

In a hearing test,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 standard deviation?

According to Chebyshev's Theorem,at least what proportion of the data will be within μ ± kσ for k = 2?

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

Find the weighted mean per capita income for the following random sample of six cities in the Midwest.

Find the coefficient of variation for IQ tests with a mean of 100 and a standard deviation of 15.

Find the z-score for an IQ test score of 125 when the mean is 100 and the standard deviation is 15.