Archives: Quiz

When using the chi-square hypothesis test and the observed frequencies are relatively close to the expected frequencies, which one of the following statements is true? A) The scenario will result in a smaller chi-square statistic, which increases the likelihood that […]

The following data represents the number of Sony TVs sold per day at a particular Costco over a random sample of five business days. The standard deviation of this sample is ________. A) 1.2 B) 1.5 C) 2.0 D) 2.6 […]

A survey of adults who typically work full-time from home recorded their current education levels. The results are shown in the table below. The probability that a randomly selected adult who works from home has less than a high school […]

A random sample of 150 mortgages in the state of Mississippi was randomly selected. From this sample, 17 were found to be delinquent on their current payment. The approximate standard error of the proportion for this sample is ________. A) […]

The following contingency table shows the number of two-bedroom apartments grouped by monthly rent and location. The probability that a randomly selected apartment from this group has a monthly rental from $800 to under $900 or is located in York […]

The table below shows the number of cars sold last month by seven employees at Concord Motors and their number of years of sales experience. Management would like to use simple regression analysis to estimate monthly car sales using the […]

We expect the average value of many sample means to be close to the population mean from which they were drawn. If you are a researcher and the purpose of the hypothesis test is to prove that your findings are […]

When the confidence interval for the difference between two means does not include zero when testing , we have support that a significant difference between population means does exist. The degrees of freedom are used to determine the critical z-score […]

An ordered pair is a set of x and y values that pertain to a specific observation. The goal of the minimax regret criterion is to minimize the decision maker’s regret of making a wrong choice. Answer: TRUE Percentile ranks […]

Business statistics are statistics applied to the business world in an effort to improve people’s decision making in fields such as marketing research, operations, finance, and advertising. When creating a frequency distribution with grouped qualitative data and 45 data points, […]

Reducing α without increasing the sample size will cause β to increase. The hypergeometric distribution is used when samples are taken from an infinite population with replacement. Answer: FALSE As long as the main factor is statistically significant with randomized […]

When using best subsets regression, select the subset with the lowest adjusted and lowest standard error. Continuous data are values based on observations that can be counted and are typically represented by whole numbers. Answer: FALSE The sample covariance measures […]

The sum of squares block (SSBL) measures the variation between the block means and the sample means. Using backward elimination regression may result in a model in which none of the independent variables are statistically significant. Answer: FALSE The degrees […]

When conducting a hypothesis test comparing two populations with independent samples, the sample sizes must be equal. Quantitative data are values that are categorical, describing a characteristic such as gender or level of education. Answer: FALSE The number of typographical […]

For a one-tail (upper) hypothesis test, if the z- or t-test statistic exceeds the critical value, we do not reject the null hypothesis. The null hypothesis is believed to be true unless there is overwhelming evidence to the contrary. Answer: […]

The range is a measure of central tendency. When the relationship between the variables is statistically significant using simple regression analysis, we have enough evidence to state that the independent variable caused the change in the dependent variable. Answer: FALSE […]

For a relatively large beta (closer to 1.0), the current trend adjustment is more affected by the most recent trend when using exponential smoothing with trend adjustment. Using the equally likely criterion you choose the alternative with the highest in […]

The expected value of sample information is the mean of a discrete probability distribution when the discrete random variable is expressed in terms of dollars. Positive autocorrelation is present in a time series when we observe a pattern of positive […]

The chi-square test of independence does not allow us to state that one variable causes a change in another variable when the null hypothesis is rejected. The multiple correlation coefficient is the percent of variation in the dependent variable explained […]

When the sample size is more than 30 and sigma is known, the population must be normally distributed to calculate a confidence interval. Forecasting errors for a time-series technique must always be non-negative (i.e., zero or positive values). Answer: FALSE […]

Nonparametric statistics can be used for data that is at the nominal or ordinal level of measurement. A symmetrical distribution is one in which the right side of the distribution looks like the mirror image of the left side of […]

The following data represents the amount of money nine randomly selected people spent on Father’s Day gifts. $120 $74 $97 $136 $80 $112 $125 $105 $96 Describe the shape of this distribution as symmetrical, left-skewed, or right-skewed. Hallmark would like […]

An issue that faces individuals investing for retirement is allocating assets among different investment choices. Suppose a study conducted 10 years ago showed that 65% of investors preferred stocks to real estate as an investment. In a recent random sample […]

Students who have completed a speed reading course have reading speeds that are normally distributed with a mean of 950 words per minute and a standard deviation equal to 220 words per minute. If two students were selected at random, […]

Cross County Bicycles makes two mountain bike models that each come in three colors. The following table shows the production volumes for last week: What is the joint probability that a product manufactured is a YZ-99 and brown? A) 0.2088 […]

The Morgan Company is interested in developing a forecast for next month’s sales. It has collected sales data for the past 12 months. After analyzing these data, if the company wishes to use double exponential smoothing with alpha = 0.20 […]

The population mean of income for adults in a particular community is known to be $28,600. Given this information, the sampling distribution of values will be less than this depending on the size of the sample used in developing the […]

The three components of the regression model-building process are model specification, model fitting, and model diagnosis. A major airline has stated in an industry report that its mean onground time between domestic flights is less than 18 minutes. To test […]

In a situation where we know the population standard deviation but wish to estimate the population mean using a 90 percent confidence interval, the critical value is z = 1.645. A major manufacturer of home electronics is interested in determining […]

Managers for a company that produces a weight loss product claim that the median weight lost over six weeks for people who use this product will be at least 20 pounds. The following data were collected from a sample of […]

In a Mann-Whitney U test, if the sample sizes are large then the test statistic can be approximated by the student’s t-distribution. The primary application for the hypergeometric probability distribution is in situations where the sampling is done without replacement […]

To test for the stopping distances of four brake systems, 10 of the same make and model of car are selected randomly and then are assigned randomly to each of four brake systems. This is a randomized complete block design. […]

A large sample Mann-Whitney U test should be used when the sample sizes exceed 20. In conducting the Wilcoxon Matched-Pairs Signed Rank test, the difference between each pair of values must be found prior to conducting any ranking. Answer: TRUE […]

The only two types of random variables are discrete and continuous random variables. A 95 percent confidence interval for a mean will contain 95 percent of the population within the interval. Answer: FALSE Sawyer & Company is a law firm […]

If a set of data has 540 values, the 3rd quartile corresponds to approximately the 135th value when the data have been arranged in numerical order. In estimating a population mean, a large sample size is generally preferable to a […]

Standard stepwise regression is a good way of identifying potential multicollinearity problems since we are able to see the impact on the model at each step that occurs when a new variable is added to the model. For instance, if […]

A report in a consumer magazine indicated that with 90 percent confidence, the mean number of hours that a particular brand light bulb lasts is between 900 and 1,100 hours. Based on this, the sample mean that produced this estimate […]

One of the variables that are being considered for inclusion in a multiple regression model is marital status of the customer. There are four possible responses listed for this variable. Based on this, four dummy variables will need to be […]

In constructing a stem and leaf diagram, there is a hard-and-fast rule for defining the stem and the leaves. In order to test the difference in populations means, samples were collected for two independent populations where the variances are assumed […]

In most processes, the process control limits are set to correspond with the specification limits on the product. Six food critics each visited and rated four different restaurants. Each critic visited each restaurant on three separate occasions and recorded a […]

If a population is skewed, the point estimate will be pushed to the right or left of the middle of the confidence interval estimate. The Nationwide Motel Company has determined that 70 percent of all calls for motel reservations request […]

When determining the sample size for a proportion, if you have no previous information available to estimate p, then the best value to use is π = 0.5. When testing whether two paired populations have equal medians and the sample […]

Lube-Tech is a major chain whose primary business is performing lube and oil changes for passenger vehicles. The national operations manager has stated in an industry newsletter that the mean number of miles between oil changes for all passenger cars […]

The Brockingham Carpet Company prides itself on high quality carpets. At the end of each day, the company quality managers select 3 square yards for inspection. The quality standard requires an average of no more than 2.3 defects per square […]

The Baker Oil and Gas Company has four retail locations, code-named A, B, C, and D. The following table illustrates the percentage of total company sales at each store and also the percentage of customers at that store who make […]

An Internet-based or emailed survey is not an alternative method of data collection. When estimating sample size, a 90 percent confidence level will result in a smaller sample size than a 95 percent confidence level. Answer: TRUE A business with […]

Two common unweighted indexes are the Paasche Index and the Laspeyres Index. The basic logic of the Wilcoxon signed rank test is that if about half the data values fall above the hypothesized median, and about half fall below, the […]

Analysis of variance can only be done for fixed effects. A pie chart is almost always constructed when the variable of interest is qualitative. Answer: FALSE The forecasting interval is the unit of time for which forecasts are made. Answer: […]

In a large sample test about a single population median, it is appropriate to employ the standard normal distribution so long as the population is also normally distributed. A bank is interested in determining whether its customers’ checking balances are […]

In a two-tailed hypothesis test the area in each tail of the rejection region is equal to α. Answer: FALSE If the observed value in a time series for period 3 is yt = 128, and the seasonal index that […]