stats quiz 1

Question 1 of 201.0 PointsA sample of 20 observations has a standard deviation of 4. The sum of the squared deviations from the sample mean is:A. 320B. 304C. 288D. 400Reset SelectionQuestion 2 of 201.0 PointsSuppose that a histogram of a data set is approximately symmetric and “bell shaped”. Approximately, what percent of the observations are within three standard deviations of the mean?A. 50%B. 99.7%C. 95%D. 68%Reset SelectionQuestion 3 of 201.0 PointsWhich of the following correctly describes the relationship between a sample and a population?A. A sample is a group of populations that are subject to observation.B. A population and a sample are not related.C. A population is a group of samples that may or may not be included in a studyD. A sample is a group of subjects selected from a population to be studied.Reset SelectionQuestion 4 of 201.0 PointsA histogram that has a single peak and looks approximately the same to the left and right of the peak is called:A. bimodalB. symmetricC. proportionalD. balancedReset SelectionQuestion 5 of 201.0 PointsWhich of the following statements is true for the following data values: 7, 5, 6, 4, 7, 8, and 12?A. Only the mean and median are equalB. The mean, median and mode are all equalC. Only the median and mode are equalD. Only the mean and mode are equalReset SelectionQuestion 6 of 201.0 PointsIf a variable has possible values –2, 6, and 17, then this variable isA. both a continuous and a discrete variableB. a discrete variableC. neither a continuous nor a discrete variableD. a continuous variableReset SelectionQuestion 7 of 201.0 PointsWhich of the following statements is true regarding the data set 10, 10, 10, 10, and 10?A. The range is zeroB. The standard deviation equals zeroC. The interquartile range equals zeroD. all of the aboveReset SelectionQuestion 8 of 201.0 PointsGender and State are examples of which type of data?A. Discrete dataB. Continuous dataC. Categorical dataD. Ordinal dataReset SelectionQuestion 9 of 201.0 PointsIf a value represents the 95th percentile, this means thatA. 95% of the time you will observe this valueB. 95% of all values are below this valueC. 95% of all values are above this valueD. there is a 5% chance that this value is incorrectReset SelectionQuestion 10 of 201.0 PointsA scatter plot would be useful forA. Showing the trend of sales, over time, of five different brands of blank DVDsB. Showing the relationship between the sales of blank CDs and blank DVDsC. Showing the top selling brands of blank DVDsD. Showing the relative number of sales of four different brands of blank DVDsReset SelectionQuestion 11 of 201.0 PointsWhich of the following indicates how many observations fall into various categories?A. The frequency tableB. The tabulation scaleC. The Likert scaleD. The sample tableReset SelectionQuestion 12 of 201.0 PointsWhich of the following are the three most common measures of central location?A. Mean, median, and standard deviationB. Mean, median, and modeC. Mean, variance, and standard deviationD. Mean, median, and varianceReset SelectionPart 2 of 3 -Question 13 of 201.0 PointsClick to see additional instructionsA sample of 150 students at a State University was taken after the final business statistics exam to ask them whether they went partying the weekend before the final or spent the weekend studying, and whether they did well or poorly on the final. The following table contains the result.Did Well in ExamDid Poorly in ExamStudying for Exam6015Went Partying2253Question 14 of 201.0 PointsClick to see additional instructionsThe following data are the base salaries, in thousands of dollars, of 50 chief executive officers for a sample of companies doing business with the state of Connecticut. That is, the first entry in the table below corresponds to a salary of $125,000. A copy of this data set can be found in the Excel Workbook called CEOSalaries.xls.125157113127201165145119148158148168117105136136125148108178179191225204104205197119209157209205221178247235217222224187265148165228239245152148115150Find the median of the CEO salaries, in thousands of dollars, rounded to 2 decimal places. Do not use a dollar sign. Note: $177,760 should be recorded as 177.76.Question 15 of 201.0 PointsClick to see additional instructionsQuestion 16 of 201.0 PointsClick to see additional instructionsThe following data are the base salaries, in thousands of dollars, of 50 chief executive officers for a sample of companies doing business with the state of Connecticut. That is, the first entry in the table below corresponds to a salary of $125,000. A copy of this data set can be found in the Excel Workbook called CEOSalaries.xls.125157113127201165145119148158148168117105136136125148108178179191225204104205197119209157209205221178247235217222224187265148165228239245152148115150Find the interquartile range of the CEO salaries, in thousands of dollars, rounded to 2 decimal places. Do not use a dollar sign. Note: $177,760 should be recorded as 177.76.Question 17 of 201.0 PointsClick to see additional instructionsA sample of 150 students at a State University was taken after the final business statistics exam to ask them whether they went partying the weekend before the final or spent the weekend studying, and whether they did well or poorly on the final. The following table contains the result.Did Well in ExamDid Poorly in ExamStudying for Exam6015Went Partying2253Question 18 of 201.0 PointsClick to see additional instructionsA sample of 150 students at a State University was taken after the final business statistics exam to ask them whether they went partying the weekend before the final or spent the weekend studying, and whether they did well or poorly on the final. The following table contains the result.Did Well on ExamDid Poorly on ExamStudying for Exam6015Went Partying2253If the sample is a good representation of the population, what percentage of those who did poorly on the final exam should we expect to have spent the weekend studying?  Place your answer in the blank, rounded to 2 decimal places. Do not use a percentage sign (%). For example, 44.44 would be a legitmate answer.Part 3 of 3 -Question 19 of 201.0 PointsA histogram is skewed to the left (or negatively skewed) if it has a single peak and the values of the distribution extend much further to the right of the peak than to the left of the peak.Reset SelectionQuestion 20 of 201.0 PointsIf you are in a class where most students do reasonably well on a test but a few pull down the class average, the histogram describing the test scores will indicate a positively-skewed distribution.Reset Selection