Business and Economic Statistics Mid-term Exam Questions with Answers.

Business and Economic Statistics Mid-term Exam Questions with Answers The main purpose of descriptive statistics is to: - Correct Answers: Summarize data in a useful and informative manner. Which of the following is an example of a continuous variable? - Correct Answers: Tons of concrete to complete a parking garage The incomes of 50 loan applicants are obtained. Which level of measurement is income? - Correct Answers: Ratio A bank asks customers to evaluate the drive-thru service as good, average, or poor. Which level of measurement is this classification? - Correct Answers: Ordinal A portion or part of a population is called a - Correct Answers: Sample The members of each basketball team wear numbers on their jerseys. What scale of measurement are these numbers considered? - Correct Answers: Nominal An example of statistics abuse may include .......... - Correct Answers: using presentation graphics that have inconsistent axis scales and/or non-(0,0) intercepts. A survey includes a question regarding marital status that has the following responses: single, married, divorced, separated, or widowed. What is the scale of measurement for this question? - Correct Answers: Nominal What level of measurement is the Centigrade temperature scale? - Correct Answers: Interval What type of variable is the potential number of gallons of gasoline pumped by a filling station during a day? - Correct Answers: Continuous What type of variable is the number of auto accidents reported in a given month? - Correct Answers: Discrete The names of the positions in a corporation, such as chief operating officer or controller, are examples of what type of variable? - Correct Answers: Qualitative Your height and weight are examples of which level of measurement? - Correct Answers: Ratio Shoe style is an example of what level of measurement? - Correct Answers: Nominal Which one of the following is NOT an example of discrete data? - Correct Answers: Ounces of cereal poured into a cereal bowl. The following table reflects choices and responses to a question about annual income. The outcome may be flawed because .................... Low High Count 0.00 10000.00 7 10000.01 20000.00 19 20000.01 30000.00 27 30000.01 40000.00 42 40000.01 50000.00 34 50000.01 Plus 9 - Correct Answers: the choices and question do not appear to be flawed. If Gallup, Harris, and other pollsters asked people to indicate their political party affiliation as Democrat, Republican, or Independent, the data gathered would be an example of which scale of measurement? - Correct Answers: Nominal A pure dichotomous variable may have how many potential responses? - Correct Answers: two A study of homes in Gulfloxi suggested the minimum house value to be $43,200 and the highest house value to be $295,870 in the selected sample. There is not a zero dollar value present in the data set. The level of data for house prices is considered to be ........ - Correct Answers: Ratio The highest level of data used for statistical analysis is ................ - Correct Answers: Ratio What type of variable is pounds of popcorn served at a movie theater? - Correct Answers: Continuous The final rankings of the top 20 NCAA college basketball teams are an example of which level of measurement? - Correct Answers: Ordinal An example of a qualitative variable is _________________. - Correct Answers: Color of ink in a pen Dr Leaf wants to better understand the characteristics of the Fall 2017 MBA729 course. There are 15 students in the class. Further, there are 118 MBA students and 1876 total registered students. Dr Leaf found the undergraduate GPA for the MBA729 students to be 3.15. Dr Leaf also understands the GPA for all registered students is 2.78. The MBA729 students should be considered a for the 15 student GPA analysis. - Correct Answers: Population Generally, the only statistic of value for categorical data represented by a number (i.e., a zip code, area code, jersey number) is the ...... - Correct Answers: count A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060, $1,840, $1,795, $1,890, $1,925, and $1,810. What are these ungrouped numbers called? - Correct Answers: Raw data When data is collected using a qualitative, nominal variable, what is true about a frequency distribution that summarizes the data? - Correct Answers: A pie chart can be used to summarize the data. When data is collected using a qualitative, nominal variable (for example academic status: freshman, sophomore, junior, senior), what is true about a frequency distribution that summarizes the data? - Correct Answers: The number of classes is equal to or less than the number of a variable's values. A student was interested in the number of tests required to be taken by college students in a semester and collected data from an unbiased random sample of students. What type of chart best represents the frequency table? - Correct Answers: Bar chart What type of chart best represents relative class frequencies for nominal and qualitative variables? - Correct Answers: Pie chart When a class interval is expressed as 100 up to 200, _______. - Correct Answers: Observations with values of 200 are excluded from the class For a relative frequency distribution, relative frequency is computed as _____________. - Correct Answers: The class frequency divided by the total frequency. The relative frequency for a class represents the ______. - Correct Answers: Percent of observations in the class relative to all the observations. A group of 100 students was surveyed about their interest in a new International Studies program. Interest was measured in terms of high, medium, or low. In the study, 30 students responded high interest, 40 students responded medium interest, and 30 students responded low interest. What is the relative frequency of students with high interest? - Correct Answers: .30 The monthly salaries of a sample of 100 employees were rounded to the nearest $10. They ranged from a low of $1,040 to a high of $1,720. If we want to condense the data into seven classes, what is the most convenient class interval? - Correct Answers: $100 A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify themselves as a Democrat or a Republican. This question is flawed because: - Correct Answers: The categories are not exhaustive. A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify their political preference, for example, Democrat, Republican, Libertarian, or another party. The best way to illustrate the frequencies for each political preference is a __________. - Correct Answers: Bar chart A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify their political preference—for example, Democrat, Republican, Libertarian, or another party. The best way to illustrate the relative frequency distribution is a __________. - Correct Answers: Pie chart In a frequency distribution, the number of observations in a class is called the class ________. - Correct Answers: Frequency Why are unequal class intervals sometimes used in a frequency distribution? - Correct Answers: To avoid a large number of empty classes In frequency distributions, classes are mutually exclusive if each individual, object, or measurement is included in only one category. - Correct Answers: True In a bar chart, the x-axis is labeled with the values of a qualitative variable. - Correct Answers: True In a bar chart, the heights of the bars represent the frequencies in each class. - Correct Answers: True A class interval, or class width, can be determined by subtracting the lower limit of a class from the lower limit of the next higher class. - Correct Answers: True To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the sum of the class frequencies. - Correct Answers: True To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the number of classes. - Correct Answers: False A pie chart is similar to a relative frequency distribution. - Correct Answers: True To construct a pie chart, relative class frequencies are used to graph the slices of the pie. - Correct Answers: True A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values. - Correct Answers: True A frequency polygon is a very useful graphic technique when comparing two or more distributions. - Correct Answers: True For any data set, which measures of central location have only one value? - Correct Answers: Mean and median The sum of the deviations of each data value from this measure of central location will always be zero. - Correct Answers: Mean Which measures of central location are not affected by extremely small or extremely large values located to the far left or right of the data? - Correct Answers: Mode and median What is the relationship among the mean, median, and mode in a symmetric distribution? - Correct Answers: They are all equal. For a data set, half of the observations are always greater than the ____. - Correct Answers: Median What is the lowest data level from which a median can be computed? - Correct Answers: Ordinal Which one of the following is referred to as the population mean? - Correct Answers: greek letter mu (µ) On a finance exam, 15 accounting majors had an average grade of 70. On the same exam, 8 marketing majors averaged 85, and 10 finance majors averaged 94. What is the weighted mean for all 33 students taking the exam? - Correct Answers: 80.91 A survey item asked students to indicate their class in college: freshman, sophomore, junior, or senior. Which measure(s) of central location would be appropriate for the data generated by that questionnaire item? - Correct Answers: Mode and median What is the median of 26, 30, 24, 32, 32, 31, 27, 23 and 29? - Correct Answers: 29 A stockbroker placed the following order for a customer: 50 shares of Kaiser Aluminum at $104 a share; 100 shares of GTE at $26.00 a share; 20 shares of Boston Edison at $9.75 a share. What is the weighted arithmetic mean price per share? - Correct Answers: 47.03 A sample of single persons receiving Social Security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839, and $965. How many observations are below the median value? - Correct Answers: 3 Over the last six months, the following numbers of absences have been reported: 7, 0, 10, 14, 9, and 0. What is the median number of monthly absences? - Correct Answers: 8 Assume a student received the following grades for the semester: History, B; Statistics, A; Spanish, C; and English, B. History and English are 5 credit-hour courses, Statistics a 4 credit-hour course, and Spanish a 3 credit-hour course. If 4 grade points are assigned for an A, 3 for a B, and 2 for a C, what is the weighted mean grade for the semester? - Correct Answers: 3.06 A sample of the paramedical fees charged by clinics revealed these amounts: $58, $49, $50, $45, $53, and $55. What is the median charge? - Correct Answers: $51.50 The times (in minutes) that several underwriters took to review applications for similar insurance coverage are 50, 230, 54, and 57. What is the median length of time required to review an application? - Correct Answers: 55.5 For the most recent three (3) years, the U.S. Department of Education reported the following number of bachelor's degrees awarded in computer science: 8,718; 11,155; 15,122. What is the annual arithmetic mean number of degrees awarded? - Correct Answers: About 11,665 A question in a market survey asks for a respondent's favorite car color. Which measure of central location should be used to summarize this question? - Correct Answers: Mode Sometimes, a data set has two values that have the highest and equal frequencies (they are tied for appearing most often). In this case, the distribution of the data can best be described as __________. - Correct Answers: Bimodal (having two modes) A disadvantage of using an arithmetic mean to summarize a set of data is that __________. - Correct Answers: It can be biased by one or several extremely small or large values to either end of the data The mean, as a measure of central location, would be inappropriate for which one of the following? - Correct Answers: Marital status (with three or more choices) of college students at a particular university What is a disadvantage of the range as a measure of dispersion? - Correct Answers: It is based on only two observations. The sum of the differences between sample observations and the sample mean is equal to _______. - Correct Answers: Zero Which of the following measures of dispersion are based on deviations from the mean? - Correct Answers: All apply Standard deviation Variance Mean deviation What is the relationship between the variance and the standard deviation? - Correct Answers: Variance is the square of the standard deviation. For a sample of similar sized all-electric homes, the March electric bills were (to the nearest dollar): $214, $191, $176, $129, $106, $96, $108, $109, $103, $121, $175, and $194. What is the range? - Correct Answers: $118 The weights of a sample of crates ready for shipment to Moscow, Russia are (in kilograms): 104, 107, 110, 106, and 108. What is the mean (absolute) deviation? - Correct Answers: 1.6 kg Sharon Jones applied for a nursing position at Memorial Garden Baptist Park Hospital. There were four (4) tiers of positions opened with hourly rates of $19.50, $23.65, $28.75, and $34.40. The number of persons currently at the respective hourly rates are 15, 8, 10, and 8 for a total of 41 employees. The interviewer suggested the average hourly rate for the employees is $26.58. What is the relevant average hourly rate? - Correct Answers: Approximately $25.47 The test scores for a class of 147 students are computed. What is the location of the test score associated with the third quartile? - Correct Answers: 111 Quartiles divide a set of observations into four equal parts. 147/4 =36.75 *q3 = 110.25 (rounded = 111) Quartiles divide a distribution into ___________. - Correct Answers: 4 equal parts In a distribution, the second quartile corresponds with the __________ - Correct Answers: Median Percentiles divide a distribution into _____________. - Correct Answers: 100 equal parts If a student places in the 99th percentile on an exam, she performed better than 99% of all students who completed the exam. Her performance is similar to a statement based on a __________. - Correct Answers: Cumulative frequency distribution What statistics are needed to draw a box plot? - Correct Answers: The minimum, maximum, median, first and third quartile values. A box plot shows ___________. - Correct Answers: The relative symmetry of a distribution for a set of data What does the interquartile range describe? - Correct Answers: The range of the middle 50% of the observations The interquartile range is graphically presented in a ___________. - Correct Answers: Box plot Outliers are clearly presented in a _____________. - Correct Answers: Box plot Using the following statistics to describe a distribution of data, what is the interquartile range? Minimum=10, Q1=25, Median=50, Q3=75, Maximum=95 - Correct Answers: 50 The box plot also shows the interquartile range of delivery times between Q1 and Q3. (Q1 25 - Q2 75) = 50 In a scatter diagram, we describe the relationship between __________. - Correct Answers: Two variables measured at the interval or ratio level In a contingency table, we describe the relationship between two variables measured at the nominal or greater level. - Correct Answers: True