Exam 3: Descriptive Statistics and Analytics: Numerical Methods

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 65th percentile?

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 mean?

The Rivertown city council is attempting to choose one of four sites (A, B, C, or D) as the location for its new emergency facility. After the new emergency facility becomes available for service, the current emergency facility will be shut down. The project manager has estimated the following response times in minutes from each of the proposed sites to the four areas that must be served by the emergency facility. The number of emergency runs from the current emergency facility to each of the four areas over the past year is as follows: Compute the weighted mean response time from the proposed locations and determine which proposed site should be selected for the new emergency facility.

Using Chebyshev's theorem, approximate the minimum proportion of the data that will be within μ ± kσ for k = 1.6.

According to a survey of the top 10 employers in a major city in the Midwest, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes, and the time spent is approximately a normal distribution. What are the times within which approximately 68.26 percent of all workers will fall?

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.

In the least squares line, ________ is defined as rise/run.

The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002. Determine the percentage change in the P/E ratios from 1999 to 2000.

A normal population has 99.73 percent of the population measurements within ________ standard deviation(s) of the mean.

The geometric mean is the rate of change that yields better wealth at the end of a set of time periods than the actual returns.

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 mean.

The measurement in a sample or a population that occurs most frequently is the ________.

If the mean, median, and mode for a given population are all equal and the relative frequency curve has matching tails to the right and left, then we would describe the shape of the distribution of the population as ________.

The average life of Canadian women is 73.75 years, and the standard deviation of the life expectancy of Canadian women is 6.5 years. Based on Chebyshev's theorem, determine the upper and lower bounds on the average life expectancy of Canadian women such that at least 90 percent of the population is included.

An initial investment of $10,000 is observed over 3 years with a geometric mean return at the end of year 3 of .512. Determine the value of the investment after 3 years.

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 10th percentile?

If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ________.

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 correlation coefficient.

Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the variance?

Another name for the 50th percentile is the ________.