Basic Statistics for Business and Economics 8th Edition

A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table: Why is the table NOT a frequency distribution? A. The number of males does not equal the sum of males that smoke

The annual income for a sample of 500 part-time students is normally distributed with a mean income of $30,000 and a standard deviation of $3,000. The income range that separates the top 25% from the lower 75% is __________. Answer: $32,010 or $32,040Feedback: The problem is to find the annual income that

If the correlation coefficient between two variables, X and Y, equals zero, what can be said of the variables X and Y? A. The variables are not related. B. The variables are dependent on each other. C. The variables are highly related. D. X causes Y. Answer: A.A correlation coefficient of zero indicates

Sampling from a population may be preferred, because studying all the items in a population may be too ____________. Answer: Cost/time consumingCollecting data is a process that is costly in terms of time and money. Sampling would be less costly than collecting information on all items in a population. Answer: Cost/time consumingCollecting

What must you know to develop a binomial probability distribution? A. The probability of success B. The probability of success and the number of trials C. The probability of success and the number of successes D. The number of trials and the number of successes Answer: B.By definition, a particular binomial distribution is specified

In multiple regression analysis, the ________ scale is used to measure a dummy variable. Answer: NominalA dummy variable is measured with a nominal scale. A dummy variable has only two possible outcomes such as "yes or no", "male or female". For multiple regression analysis, outcomes are coded as 0 or 1. Answer:

In an ANOVA table for a multiple regression analysis, the regression mean square is __________. A. The treatment sum of squares divided by the regression degrees of freedom B. n - (k + 1) C. The regression sum of squares divided by the regression degrees of freedom D. The total sum of squares divided

A variable such as eye color is also referred to as a(n) _____________ variable. Answer: QualitativeQualitative variables measure observable attributes such as eye color. Answer: QualitativeQualitative variables measure observable attributes such as eye color. Answer: Qualitative Qualitative variables measure observable attributes such as eye color. High school students were interested in a teacher's claim that

In one class, a statistics professor wants to compare grades on the first and second exams. This is an example of ________________ observations. Answer: Paired or dependentEach student in the class has grades on the two exams. So there is a pairing of the scores for each student. The samples are

The regression equation is = 29.29 - 0.96X, the sample size is 8, and the standard error of the slope is 0.22. What is the critical value to test the significance of the slope at the 0.01 significance level? A. z = +2.576 B. t = +3.707 C. t = +3.355 D. t =

In a contingency table, we describe the relationship between ________. A. Two variables measured at the ordinal or nominal level B. Two variables, one measured as an ordinal variable and the other as a ratio variable C. Two variables measured at the interval or ratio level D. A variable measure on the interval or

When testing the difference between two dependent population means, the test statistic is based on a ______________. A. Pooled variance B. Standard deviation of the differences C. Pooled proportion D. Sum of the population variances Answer: B. When the samples are dependent, we find the difference between the paired or related observations. The test statistic

For a data set, half of the observations are always greater than the ____. A. Median B. Mode C. Mean D. Standard deviation Answer: A. Half of the observations will be larger than the median and half smaller. This is not necessarily true of the mean and mode. In the regression equation, what does the letter

A study of interior designers' opinions with respect to the most desirable primary color for executive offices showed that: What is the probability that a designer does not prefer red? A. 1.00 B. 0.77 C. 0.73 D. 0.23 Answer: B. Using the complement rule, P(red) = 92/400 = 0.23. Therefore, P(not red) = 1.00 - 0.23

The major advantage of ordinal data over nominal data is that it allows for _________________. Answer: Ranking or orderingOrdinal data can be ranked or ordered. Nominal data are labels or attributes that do not have any logical order. Answer: Ranking or orderingOrdinal data can be ranked or ordered. Nominal data are labels

A New York newspaper reported the average gasoline prices in four metropolitan areas and used a bar chart to illustrate the differences. What type of statistics was shown? What activities did the newspaper use to make the report? Answer: The newspaper used descriptive statistics. The statistical techniques used to make

Elly's Hotdog Emporium is famous for its chilidogs. Elly's latest sales indicate that 30% of the customers order their chilidogs with hot peppers. Suppose 15 customers are selected at random. What is the probability that between two and six people inclusive want hot peppers? Answer: 0.834Feedback: Applying the binomial probability formula

Refer to the following distribution of ages: What is the class midpoint of the highest class? A. 54 B. 55 C. 64 D. 65 Answer: D.The highest class is "60 up to 70." The class midpoint is the lower limit (60) plus half of the class interval: 10 = 5, or $60 + 5 =

In multiple regression analysis, a dummy variable is ____________. A. An additional quantitative variable B. A nominal variable with three or more values C. A nominal variable with only two values D. A new regression coefficient Answer: C.In multiple regression, a dummy variable is a nominal variable with only two possible outcomes. For analysis,

A personnel manager is concerned about absenteeism. She decides to sample employee records to determine if absenteeism is distributed evenly throughout the six-day workweek. The null hypothesis is: Absenteeism is distributed evenly throughout the week. Use the 0.01 level of significance. The sample results are: How many degrees of freedom are

A telemarketing firm is monitoring the performance of its employees based on the number of sales per hour. One employee had the following sales for the last 19 hours. Answer: For the distribution of number of sales per hour, 50% are equal or greater than ___________.The median or 5 sales per

Which of the following is NOT necessary to determine how large a sample to select from a population? A. The level of confidence in estimating the population parameter B. The size of the population C. The maximum allowable error in estimating the population parameter D. An estimate of the population variation Answer: B. The formulas

Records on a fleet of trucks reveal that the average life of a set of spark plugs is normally distributed with a mean of 22,100 miles. The fleet owner purchased 18 sets and found that the sample average life was 23,400 miles; the sample standard deviation was 1,412 miles. What

The shape of the F distribution is _____________________. Answer: Positively skewedThe F distribution is positively skewed, but as the degrees of freedom in both the numerator and the denominator increase, the distribution approaches the normal distribution. Answer: Positively skewedThe F distribution is positively skewed, but as the degrees of freedom in both

When dividing a population into subgroups so that a random sample from each subgroup can be collected, what type of sampling is used? A. Simple random sampling B. Systematic sampling C. Stratified random sampling D. Cluster sampling Answer: C. In stratified sampling, we divide the population into strata and then randomly select samples from each

Accounting procedures allow a business to evaluate their inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO

For any data set, Chebyshev's Theorem estimates the proportion of observations that occurs within k standard deviations of the mean, where k is greater than 1.0. Answer: TRUE The variance inflation factor is used to select or remove independent variables to reduce the effects of multicollinearity in a multiple regression equation. Answer:

For any distribution, there are an equal number of values above and below the mean. Answer: FALSE There are an equal number of observations above and below the median. The central limit theorem states that if the sample size, n, is sufficiently large, the sampling distribution of the means will be approximately

A frequency distribution for qualitative data has class limits. Answer: FALSEQualitative data is not numeric, so there cannot be class limits. Answer: FALSEQualitative data is not numeric, so there cannot be class limits. Answer: FALSE Qualitative data is not numeric, so there cannot be class limits. A statistics professor wants to compare grades in

The chi-square distribution is _____________. A. Positively skewed B. Negatively skewed C. Normally distributed D. Uniformly distributed Answer: A.The chi-square distribution is positively skewed. As the degrees of freedom increase, the distribution will approach the normal distribution. Answer: A.The chi-square distribution is positively skewed. As the degrees of freedom increase, the distribution will approach the

The regression equation is used to estimate a value of the dependent variable Y based on a selected value of the independent variable X. Answer: TRUE A p-value is the same as a stated significance level. Answer: FALSE A p-value is based on the computed test statistic. The researcher sets the significance level. To

From past history, the scores on a statistics test are normally distributed with a mean score of 70 and a standard deviation of 5. To earn a "C" on the test, a student must be in the top 25% of the class. A student would need to score at least

For hypotheses that compare two population means, what test statistic is used when the population standard deviations are unknown? Answer: The t-statistic Answer: The t-statistic Answer: The t-statistic The following frequency distribution shows the distribution of delivery times (in days) for swimstuff.com customer orders during the last month. How many orders were delivered in

Based on the central limit theorem, the sample mean can be used as a good estimator of the population mean, assuming that the size of the sample is sufficiently large. Answer: FALSE The results of the central limit theorem refer to the distribution of the sample means. It states that if

To employ ANOVA, the populations being studied must be approximately normally distributed. Answer: TRUE Answer: TRUE Answer: TRUE A marketing research agency was hired to test a new DVD player. Consumers rated it outstanding, very good, fair, or poor. The level of measurement for this experiment is ordinal. Answer: TRUE

An ANOVA has three sources of variation. They are _____, _____, and _____. Answer: Total, treatment, and errorAn ANOVA with three sources of variation would be complete with total, treatment, and error sources of variation. Answer: Total, treatment, and errorAn ANOVA with three sources of variation would be complete with total, treatment,

Quartiles divide a distribution into ___________. A. 2 equal parts B. 4 equal parts C. 10 equal parts D. 100 equal parts Answer: B.Quartiles divide a distribution into four equal parts. Answer: B.Quartiles divide a distribution into four equal parts. Answer: B. Quartiles divide a distribution into four equal parts. Refer to the following distribution: What is the relative

Twenty-one executives in a large corporation were randomly selected to study the effect of several factors on annual salary (expressed in $000s). The factors selected were age, seniority, years of college, number of company divisions they had been exposed to, and the level of their responsibility. The results of the regression

A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected and their times (in seconds) to access the website with the old and new designs were recorded. The results follow. What is the value of the

For the following distribution of heights, what are the limits for the class with the greatest frequency? A. 64 and up to 70 B. 65 and 69 C. 65 and up to 70 D. 69.5 and 74.5 Answer: C.The frequency table has three classes with frequencies of 10, 70, and 20. The class 65"

A random sample of 20 female executives from companies with assets over $1 million was selected and asked for their annual income and level of education. The ANOVA comparing the average income among three levels of education rejected the null hypothesis. The Mean Square Error (MSE) was 250. The following

The arrival of customers at a service desk follows a Poisson distribution. If they arrive at a rate of four every five minutes, what is the probability that more than four customers arrive in a five-minute period? Answer: 0.3711Feedback: Applying a Poisson probability table, find the column where = 4,