Exam 26: Statistics and Data Analysis

A recent survey of online shoppers asked them to indicate the primary reason they shop via the Internet.The table summarizes responses by reason and gender.What percent of respondents who cited Greater Selection as the primary reason they shop online were females?

An advocacy group is investigating whether gender has an effect on job category in large investment firms.Given the results shown in the table below, which of the following statements is true about gender and job category?

A correlation of zero between two quantitative variables means that ________________________ .

Suppose that a manufacturer is testing one of its machines to make sure that the machine is producing more than 97% good parts The test results in a P-value of 0.102.In reality, the machine is producing 99% good parts.What probably happens as a result of our testing?

Suppose that six different e-readers were evaluated by two senior citizen consumer groups using rankings from 1 (best) to 6 (worst).What nonparametric method should be used to determine the association between these rankings?

Which of those variables about German Shepherds is most likely to be described by a Normal model?

Double-blinding in experiments is important so that ________________________ . I.The evaluators do not know which treatment group the participants are in. II.The participants do not know which treatment group they are in. III.No one knows which treatment any of the participants is getting.

A customer service center keeps track of the number of complaints received each day about one of their new products.The numbers of complaints received over the last 11 day period are 19, 18, 22, 21, 17, 18, 22, 19, 16, 23, and 25.The median for this sample of data is

A major customer for a vendor of plastic containers requires that its containers have a volume of 10,000 cubic inches with a tolerance of 50 cubic inches.Forty subgroups of five containers each were selected periodically from the production process.The average of the means across all subgroups was found to be 10,012 cubic inches and the average range was 48 cubic inches.The lower and upper control limits for the X-bar chart are ________________________ .

A regression analysis of company profits and the amount of money the company spent on advertising produced a R² = 0.72.Which of these is true? I.This model can correctly predict the profit for 72% of companies. II.72% of the variance in company profit can be accounted for by the model. III.On average, companies spend about 72% of their profits on advertising.

Estimated profits for an investor would depend on how successful a bailout bill would be in helping the U.S.economy.The estimated annual return for two different investment strategies are shown in the following table.If there is a 30% chance that the economy will decline, 50% that there will be no change and 20% chance that it will rebound, the standard deviation associated with the investment strategy of allocating 80% to stocks and 20% to bonds is ________________________ .

An advocacy group is investigating whether gender has an effect on job category in large investment firms.She surveyed a sample of firms with the results shown below.The most appropriate display for these data is a ________________________ .

Real estate agencies keep track of housing prices in a given area.Suppose they also provide their clients with quarterly median selling prices for homes in a given area for the past three year period.These data are ________________________ .

As a result of the financial crisis on Wall Street in September 2008 that required federal government intervention, a survey showed that 40% of Americans reallocated their investments to reduce exposure to the stock market.What is the probability that out of 5 randomly selected Americans, none will have reallocated their investments in this way?

A least squares estimated regression line has been fitted to a set of data and the resulting residual plot is shown.Which is true?

Which of the following statements about a residual plot is true?

A real estate agency, located in a metropolitan area in the northeastern U.S., kept data on the various types of properties purchased in the area.Historically, 15% of purchases were for condominiums, 30% were for townhouses, 40% for single family homes, 10% for commercial properties and 5% for land.With changing demographics, the agency wondered if the current distribution matches the historical distribution.Recent data showed the following: Which Chi-square test is most appropriate for this situation?

A company counts and records the number of data entry errors made on the first order form completed each day for a month (control charting).An appropriate control chart to use for these data is the ________________________ .

A professor divided the students in her business class into three groups: those who have never taken a statistics class, those who have taken only one semester of a statistics class, and those who have taken two or more semesters of statistics.The professor randomly assigns students to groups of three to work on a project for the course. If 65% of the students have never taken a statistics class, 15% have taken only one semester of a statistics class, and the rest have taken two or more semesters of statistics, what is the probability that the first groupmate you meet has studied at least two semesters of statistics?

Suppose a school district decides to randomly test high school students for attention deficit disorder (ADD).There are three high schools in the district, each with grades 9-12.The school board pools all of the students together and randomly samples 250 students.Is this a simple random sample?