Straighterline Business Stats Final Questions With Complete Solutions The main purpose of descriptive statistics is to - - Summarize data in a useful and informative manner Which word is NOT part of the definition of descriptive statistics? - - Predicting A marketing class of 50 students evaluated the instructor using the following scale: superior, good, average, poor, and inferior. The descriptive summary showed the following survey results: 2% superior, 8% good, 45% average, 45% poor, and 0% inferior. - - c. Most students rated the instructor as poor or average. What type of variable is the number of robberies reported in your city? - - Quantitative The Nielsen Ratings break down the number of people watching a particular television show by age. What level of measurement is age? - - Ratio What level of measurement is a person's "favorite sport"? - - Nominal The final rankings of the top 20 NCAA college basketball teams are an example of which level of measurement? - - Ordinal What level of measurement is the Centigrade temperature scale? - - Interval 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? - - Nominal A group of women tried five brands of fingernail polish and ranked them according to preference. What level of measurement is this? - - Ordinal Shoe style is an example of what level of measurement? - - Nominal When TV advertisements report "2 out of 3 dentists surveyed indicated they would recommend Brand X toothpaste to their patients," an informed consumer may question the conclusion because the: - - Advertisement does not include the total number of dentists surveyed A sample of the paramedical fees charged by clinics revealed these amounts: $55, $49, $50, $45, $52, and $55. What is the median charge? - - 51.00 For a data set with an odd number of observations that have been sorted from smallest to largest values, where is the median located? - - (n + 1)/2 Assume a student received the following grades for the semester: History, B; Statistics, A; Spanish, C; and English, C. 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? - - 2.76 A disadvantage of using an arithmetic mean to summarize a set of data is that __________. - - It can be biased by one or two extremely small or large values 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? - - Mode and median The times (in minutes) that several underwriters took to review applications for similar insurance coverage are 50, 230, 52, and 57. What is the median length of time required to review an application? - - 54.5 For the most recent seven years, the U.S. Department of Education reported the following number of bachelor's degrees awarded in computer science: 4,033; 5,652; 6,407; 7,201; 8,719; 11,154; 15,121. What is the annual arithmetic mean number of degrees award ed? - - About 8,327 Which of the following measures of dispersion are based on deviations from the mean? - - All apply From the easiest to the hardest "ease of interpretation," rank the measures of dispersion. - - Range, mean deviation, variance The weights of a sample of crates ready for shipment to Moscow, Russia are (in kilograms): 103, 97, 101, 106, and 103. What is the mean deviation? - - 2.4 kg A sample of assistant professors on the business faculty at state -supported institutions in Ohio revealed the mean income to be $72,000 for nine months, with a standard deviation of $3,000. Using Chebyshev's Theorem, what proportion of the faculty earns mo re than $66,000, but less than $78,000? - - At least 75% Based on the Empirical Rule, what percent of the observations will lie between plus or minus two standard deviations from the mean? - - 95% What is the relationship between the variance and the standard deviation? - - Variance is the square of the standard deviation. What statistics are needed to draw a box plot? - - The minimum, maximum, median, first and third quartiles A box plot shows ___________. - - The relative symmetry of a distribution for a set of data A dot plot can be used to show _________________. - - The distribution for a quantitative variable 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 __________. - - Cumulative frequency distribution To locate the percentile for a given observation in a data set, the data must be ___________. - - Sorted and listed from the minimum to the maximum values
