Exam 3: Descriptive Statistics: Numerical Methods

According to Chebyshev's Theorem,at least what proportion of the data will be within μ ± kσ for k = 1.6?

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 65^th percentile?

An interval that contains a specified percentage of the individual measurements is called a(n)_______________ interval.

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 65^th percentile?

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: 378,361,350,375,200,391,375,368,321. What is the mean?

Which of the following is influenced the least by the occurrence of extreme values in a sample?

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

As a measure of variation,the sample ___________ is easy to understand and compute.It is based on the two extreme values and is therefore a highly unstable measure.

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 IQR?

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 mode?

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 third quartile?

At the end of 2007,the IRA owned by Joe Smith had a value of $1.2 million.With a rate of return of -29.75 percent in 2008 and a rate of return of 2.98 percent in 2009,calculate the geometric mean rate of return for the two-year period.

When calculating the geometric mean,a quantity of 1 is added to the n^th root of the product (1 + R₁)(1 + R₂)...(1 + R_n).

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 standard deviation?

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 99.73 percent of all workers will fall?

In the calculation of a mean for grouped data,___________ are used.

The population mean is the average of the population measurements.

The range of the measurement is the largest measurement plus the smallest measurement.

The median is the value below which and above which approximately 50 percent of the measurements lie.

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.