Q&A Hero

Q: You are given the following data: 23 34 11 40 25 47 Assuming that the data reflect the population of interest, the mean of the population is 36.00.

Q: You are given the following data: 23 34 11 40 25 47 Assuming that the data reflect a sample from a larger population, the sample mean is 30.00.

Q: You are given the following data: 23 34 11 40 25 If these data were considered to be a population and you computed the mean, you would get the same answer as if these data were considered to be a sample from a larger population.

Q: The marketing manager for Voice-talk, a cell phone company, has taken a sample of 300 customers from the list of 4,356 total customers. The mean monthly bill for the last October based on the sample data is $45.62. The manager should realize that the mean bill for all 4,356 customers will actually be higher than $45.62.

Q: The symbol μ is used to represent the sample mean.

Q: A statistic is a value that describes a population characteristic while a parameter is computed from a sample.

Q: The Parks and Recreation manager for the city of Detroit recently submitted a report to the city council in which he indicated that a random sample of 500 park users indicated that the average number of visits per month was 4.56. This value should be viewed as a statistic by the city council.

Q: The owner of a local gasoline station has kept track of the number of gallons of regular unleaded sold at his station every day since he purchased the station. This morning, he computed the mean number of gallons. This value would be considered a statistic.

Q: A statistic is just another name for a parameter.

Q: If after graphing the data for a quantitative variable of interest, you notice that the distribution is highly skewed in the positive direction, the measure of central location that would likely provide the best assessment of the center would be the median.

Q: Which of the following is not considered desirable when constructing a frequency distribution for continuous data? A) Open-ended classes B) Mutually exclusive classes C) Equal-width classes D) All-inclusive classes

Q: Which of the following is an acceptable format for setting up class boundaries for a frequency distribution? A) 20 to under 40 B) 20 to 40 C) 200 to 299.99 D) All of the above.

Q: A common rule of thumb for determining how many classes to use when developing a frequency distribution with classes is: A) between 5 and 20 classes. B) no fewer than 6 classes. C) equal to 0.25 times the number of data values. D) at least 10 classes.

Q: Frequency distributions can be formed from which of the following types of data? A) Both discrete and continuous B) Discrete only C) Continuous only D) Only qualitative data

Q: Recently a study of fans attending the New York Mets baseball games was conducted and 500 fans were surveyed. In forming a frequency distribution of the number of miles fans traveled from home to the stadium, it was found that 247 fans traveled between 0 and 5 miles. Based on this information what was the relative frequency for this class? A) 0.247 B) 0.30 C) 0.494 D) Can't be determined without more information.

Q: The Maple Grove Hotel manager has collected data on the number of rooms occupied each evening for the past 700 nights. The fewest rooms occupied during that period was 11 and the most was the capacity, 430. Based on this information, which of the following would be reasonable class limits for the first class if the manager wishes to use 8 classes to develop a frequency distribution? A) 0 to 40 B) 10 to < 65 C) 11 to 19 D) 0 to 52.38

Q: A histogram is most commonly used to analyze which of the following? A) Nominal level data B) Quantitative data C) Time-series data D) Ordinal data

Q: In analyzing a single quantitative variable, you will generally choose to use a scatter diagram if the variable is measured over time and a histogram if the variable is cross-sectional.

Q: On a scatter diagram, the independent variable should be placed on the horizontal axis and the dependent variable should be placed on the vertical axis.

Q: Roscoe and Associates makes computer software for use in the telecommunications industry. Recently, managers at the company collected data for the year 2001 on three variables: total dollars spent on research and development, total sales dollars, and total employee salaries. To graphically present these three variables, the managers would be justified in using a line chart with all three variables plotted.

Q: A scatter diagram can show whether a pair of variables has a strong or weak relationship, and also whether it is linear or curved.

Q: A scatter diagram can show that the relationship between two variables is actually nonlinear.

Q: If a scatter diagram shows points that are reasonably aligned and are sloping downward from left to right, this implies that there is a negative linear relationship between the two variables.

Q: If two variables are graphed on the same line chart, two separate scales are always required.

Q: Scatter diagrams can be used for either quantitative or qualitative data.

Q: When developing a scatter diagram, it is appropriate to connect the points on the graph with straight lines or the lines can be omitted.

Q: A study at State University involved an analysis of students' GPAs and the number of hours that they work at jobs off-campus. An appropriate graph to display the relationship between these two variables might be a scatter diagram.

Q: The J.B. Hanson Company is interested in analyzing the relationship between end-of-the-week inventory levels and sales for the same week. The graph that most likely would be used to show this relationship is a histogram.

Q: To show the relationship between amount of rainfall and the number of car accidents, the best type of graph to use is a scatter diagram.

Q: Sawyer & Company is a law firm in Dallas, Texas. Recently, the administrative manager prepared a report for the managing partners that showed the number of court cases handled by the firm monthly over the past three years. One of the objectives of graphing these data might have been to identify a trend in the number of court cases.

Q: Sawyer & Company is a law firm in Dallas, Texas. Recently, the administrative manager prepared a report for the managing partners that showed the number of court cases handled by the firm monthly over the past three years. It was appropriate for her to use a line chart in this case.

Q: A major insurance company believes that for drivers between 16 years of age and 60 years of age, the number of accidents per year tends to decrease as age increases. If this is the case, a scatter diagram should show a negative relationship between the two variables.

Q: A scatter diagram is a line graph without the points connected by a line.

Q: A university recently collected data for a sample of 200 business majors. One variable collected was the number of credits left to be taken before graduation. This variable could effectively be displayed using a line chart.

Q: In a scatter plot the points should always be connected with a line.

Q: In preparing a line chart, the horizontal axis shows time and the vertical axis shows the value of the variable of interest.

Q: If the Viking Sales Company plans to display the sales for each of its six major products for the year 2001, an effective chart to do this would be a histogram.

Q: A stem and leaf diagram is more appropriate for graphically displaying a joint frequency distribution than is a histogram since the stems can be used to display one variable while the leaves can be used to display the second variable.

Q: In constructing a stem and leaf diagram, there is a hard-and-fast rule for defining the stem and the leaves.

Q: A study was recently conducted in which makers of toothpaste tracked sales for the month at different stores in a market area. The variable of interest was the number of units sold. The numbers ranged from 1,200 to 22,700. In this case, the stems in a stem and leaf diagram might be values such as 1 and 22 while the leaves would be 200 and 700.

Q: One of the differences between a stem and leaf diagram and a histogram is that even for variables involving a large number of different values, the stem and leaf diagram shows the individual data values whereas the histogram requires you to group the data and lose the individual values.

Q: A stem and leaf diagram is most similar to a bar chart.

Q: When developing a bar chart, it is usually preferable to organize the bars in order from high to low.

Q: The difference between bar charts and histograms is that bar charts always show percentage while histograms always show frequency.

Q: The Wilson company monitors customer complaints and organizes these complaints into six distinct categories. Over the past year, the company has received 534 complaints. One possible graphical method for representing these data would be a histogram.

Q: In situations involving two or more variables, both histograms and bar charts can be used for multiple variables on the same graph.

Q: A pie chart is almost always constructed when the variable of interest is qualitative.

Q: A tire store manager has collected data showing the number of tires of each brand sold during the past month. A bar chart might be effective in graphically illustrating which brands tend to sell best at this store.

Q: Bar charts can show either frequency or percentage.

Q: Bar charts can typically be formed with the bars vertical or horizontal without adversely affecting the interpretation.

Q: The regional sales manager for a medical supply company recently collected data on the reasons why customers returned the merchandise for a refund. She actually formed a frequency distribution for this variable. It would now be acceptable to construct a bar chart to graphically display the results.

Q: Histograms cannot have gaps between the bars, whereas bar charts can have gaps.

Q: A bar chart is the same as a histogram.

Q: In constructing a histogram for a joint frequency distribution, the histogram will have the most meaning for the decision maker if there are no gaps between the bars on the histogram.

Q: In a study involving car owners, one question asked the owner for the number of miles driven last year. A second question asked the owner for the age of the vehicle. A histogram would be useful for analyzing the relationship between miles driven and the age of the vehicle.

Q: In a study involving car owners, one question asked the owner for the number of miles driven last year. A second question asked the owner for the age of the vehicle. A joint frequency distribution would be useful for determining whether newer cars tend to be driven more miles than older cars.

Q: A histogram is an effective tool for graphically describing a joint frequency distribution.

Q: An ogive is a graph of a joint frequency distribution.

Q: In Excel a joint frequency distribution table can be created using a tool called PivotTable.

Q: Two separate frequency distributions for two variables provide the same information as one joint frequency distribution involving the same two variables.

Q: Another name for a joint frequency distribution is a cross-tabulation table.

Q: If you have constructed a joint frequency distribution manually and now wish to convert it to a joint relative distribution, the proper method is to divide each cell frequency by the cell's row total.

Q: An ogive is a graph that shows cumulative relative frequency.

Q: In Excel, joint frequency distributions can be generated using the Pivot Table feature under the Data tab.

Q: A histogram can be used to display a joint frequency distribution between two quantitative variables.

Q: A recent study of students at the university contained data on year in school and student age. An appropriate tool for analyzing the relationship between these two variables would be a joint frequency distribution.

Q: If a manager is interested in analyzing the relationship between the age of customers and the dollar volume of business that is done in the store, a relative frequency distribution would be most appropriate.

Q: A joint frequency distribution can be constructed for either quantitative or qualitative data.

Q: A joint frequency distribution is used to describe the number of occurrences where two observations in a data set have the same value.

Q: If you wish to construct a graph of a relative frequency distribution, you would most likely construct an ogive.

Q: When using the Histogram tool in Excel to construct a frequency distribution and histogram, if the first bin value is 10 and the second bin value is 20, the frequency count for the second class will include all values from 10 up to, but not including, 20.

Q: When using the Histogram tool in Excel to construct a frequency distribution and histogram, the bins represent the upper class limits.

Q: When the Histogram tool in Excel is used to construct a frequency distribution and histogram, the default histogram is in the proper format and will require only that you add appropriate labels.

Q: When a histogram is constructed for discrete numerical data, there should be spaces between the bars of the histogram.

Q: Consider a situation in which both a frequency distribution and a relative frequency distribution have been developed for the same quantitative variable. If histograms are constructed from each distribution, the graphs will appear to have the same shape.

Q: In a recent study of retail daily sales by stores at a mall in Kansas, the minimum daily sales was $700 and the maximum was $51,000. If you wish to construct a frequency distribution with 10 classes, the minimum class width would be $5,100.

Q: A histogram can be constructed for data that are either quantitative or qualitative.

Q: After developing a frequency distribution for a quantitative variable, a histogram can be developed with the horizontal axis representing the values of the variable and the vertical axis representing the frequency of occurrence in each class or group.

Q: In a recent study at First National Bank, a frequency count was made for the variable marital status for the bank's 10,000 customers. It would also be appropriate to develop a histogram for this variable to show how marital status is distributed.

Q: A histogram can be created for discrete or continuous data.