Exam 3: Descriptive Statistics: Numerical

The following data represent the daily demand (y in thousands of units) and the unit price (x in dollars) for a product. Daily Demand (y) Unit Price (x) 47 1 39 3 35 5 44 3 34 6 20 8 15 16 30 6 ​ a. Compute and interpret the sample covariance for the above data. b. Compute and interpret the sample correlation coefficient.

​In a box plot, data value x is considered an outlier if

The following frequency distribution shows the time (in minutes) that a sample of students uses the computer terminals per day. Time Frequency 20-39 2 40-59 4 60-79 6 80-99 4 100-119 2 ​ a. Compute the mean. b. Compute the variance. c. Compute the standard deviation. d. Compute the coefficient of variation.

From a population of size 400, a random sample of 40 items is selected.The median of the sample

The number of hours worked per week for a sample of ten students is shown below. Student Hours 1 20 2 0 3 18 4 16 5 22 6 40 7 8 8 6 9 30 10 40 ​ a. Determine the median and explain its meaning. b. Compute the 70th percentile and explain its meaning. c. What is the mode of the above data? What does it signify?

When data are positively skewed, the mean will usually be

Geometric mean is a measure of

A researcher has collected the following sample data.The mean of the sample is 5. 3 5 12 3 2 The standard deviation is

Consider a sample with the following data values. ​ 462 490 350 294 574 ​ Compute the Z scores for the above five observations.

A private research organization studying families in various countries reported the following data for the amount of time 4-year-old children spent alone with their fathers each day. Time with Dad Country (minutes) Belgium 30 Canada 44 China 54 Finland 50 Germany 36 Nigeria 42 Sweden 46 United States 42 For the above sample, determine the following measures: a. The mean b. The standard deviation c. The mode d. The 75th percentile

For the following frequency distribution (assume the data represent a population), Class Frequency 70-79 5 80-89 9 90-99 11 100-109 9 110-119 6 ​ a. Compute the mean. b. Compute the standard deviation.

The table below shows the population growth rate of a city for the years 2008 through 2012. Year Population Growth Rate 2008 0.8923 2009 1.0587 2010 1.1934 2011 1.2345 2012 1.0995 ​ a. Compute the geometric mean. b. What has been the percentage growth in the population of the city between 2008 to 2012?

The mean of the sample

The value which has half of the observations above it and half the observations below it is called the

The hourly wages of a sample of eight individuals is given below. Individual Hourly Wage (dollars) A 27 25 20 10 12 14 17 19 For the above sample, determine the following measures: a. The mean. b. The standard deviation. c. The 25th percentile.

The geometric mean of 1, 2, 4, and 10 is

Global Engineers hired the following number of Class 1 engineers during the first six months of the past year.(Assume the data represents a sample.) ​ No. of Class 1 Month Engineers Hired January 3 February 2 March 4 April 2 May 6 June 0 ​ a. Determine the mean, the median, the mode, and the range for the above data. b. Compute the variance and the standard deviation. c. Compute the first and the third quartiles. d. Compute the z-scores for the months of May and June.

The coefficient of variation is

The interquartile range is

When computing the mean, the smallest value