Exam 3: Descriptive Statistics: Numerical Methods

Quality control is an important issue at ACME Company which manufactures light bulbs.In order to conduct testing of 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 are the inner fences?

The average lateness for one of the top airline companies is 10 minutes.The variance of the lateness measure is calculated as 9.An airplane arrived 13 minutes after the stated arrival time.Calculate the Z-score for this particular airplane's lateness.

If the median of a data set is 760 and the upper quartile is 950,and the lower quartile is 650,what is the interquartile range?

A normal population has 99.73 percent of the population measurements within _____ standard deviations of the mean.

In a symmetric population,the median equals the mode.

Quality control is an important issue at ACME Company which manufactures light bulbs.In order to conduct testing of 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 range?

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

The population mean is the average of the population measurements.

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

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

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

In a statistic class,10 scores were randomly selected with the following results were obtained: 74,73,77,77,71,68,65,77,67,66 What are the inner fences?

The following frequency table summarizes the ages of 60 shoppers at the local grocery store. The sample mean for the above frequency table is calculated as 36.25.Calculate the approximate sample standard deviation for this data set.

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 stop watch 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?

Which percentile describes the first quartile,Q1?

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

In a survey of 550 randomly-selected college statistic students were surveyed on their impressions of their course,instructor and textbook.The results are as follows: Of the students who thought their textbook was very hard to read,50 also thought that the quality of the course was "poor".What proportion of students who think that their textbook was "hard" also thought their course was "poor".

According to Chebyshev's theorem,how many standard deviations from the range would include at least 80% of the values?

The company financial officer was interested in the average cost of PCs that had been purchased in the past six months.A random sample of the price of 10 computers was taken 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 IQR?

Quality control is an important issue at ACME Company which manufactures light bulbs.In order to conduct testing of 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?