Exam 2: Describing Data: Numerical

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A sample of 26 offshore oil workers took part in a simulated escape exercise,resulting in the accompanying data on time (sec)to complete the escape: -What are the values of and the median when the observations are re-expressed in minutes?

Describe the shape of the distribution of the number of trades per month for these 10 clients.Justify your answer.

The advantage of Chebyshev's theorem is that its applicability extends to any population regardless of its shape.However,it is within this guarantee that its major drawback lies.

If a distribution is highly skewed,what measure of central tendency should be avoided?

Any set of ordinal,interval or ratio level data may only have one mode.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The following numbers represent the distance,in miles,that randomly selected ten employees of a firm must travel each way to work from home: 6.5,14.8,18.6,6.5,17.4,12.3,1.9,12.9,11.1,and 8.0. -Calculate the mean number of miles driven by the ten employees.

Chebyshev's Theorem says that within two standard deviations of the mean,you will always find at least 88.9% of the data.

What conclusions can you draw about the relationship between weight and fuel efficiency?

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A sample of 26 offshore oil workers took part in a simulated escape exercise,resulting in the accompanying data on time (sec)to complete the escape: -Calculate the values of the sample mean and median.

The mean,median,and mode address questions concerning the location of the center of a data set.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider the following scores on a 20 point aptitude test for two samples of eight students each: Sample 1: 18,19,17,15,14,20,14,and 16 Sample 2: 14,15,13,11,10,16,10,and 12 -Calculate the variance for the scores in sample 1.

Which of the following measure of dispersion is based on deviations from the mean?

Information about the frequency of sales of a business inventory product's size or color can best be described by the:

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The police lieutenant in charge of the traffic division has reviewed the number of traffic citations issued per day by each of the 10 police officers in his division.The data were: 13,21,12,34,31,13,22,26,25,and 23. -What is the first quartile of the number of citations issued per day?

A college placement office conducted a survey of 100 engineers who had graduated from Stanford University.For these engineers,the mean salary was computed to be $72,000 with a standard deviation of $8,000.The percentage of these engineers who earn more than $96,000 or less than $48,000 is:

Suppose that you are working with a data set and want to check for any outliers.What should you do? Suppose you detect an outlier.What are some of your options,and how would you make your decision?

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Starting with a sample of two values 70 and 100,add three data values to your sample to obtain a new sample with certain statistics. -What are the three data values such that the new sample has a mean of 100? Justify your answer.

The manager of the help-line at a local software manufacturing firm collected data on the number of calls the help desk received per shift for the last 100 days.The data is summarized in the table below. What is the estimated mean number of calls per night? What is the estimated standard deviation?

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The annual percentage returns on two stocks over a 7-year period were as follows: -Compare the standard deviations of these two population distributions.

Although the range and interquartile range measure the spread of data,both measures take into account only two of the data values,regardless of the size of the data.