Statistics (982 problems)

Managers at all levels of an organization need adequate information to perform their respective task. One study investigated the effect the source has on the dissemination of information. In this particular study the sources of information were superior, peer and subordinate. In each case, a measure of dissemination was obtained, with higher values indicating greater dissemination of information. Using and the following data, test whether the source of information significantly affects dissemination. What is your conclusion, and what does it suggest about the use and dissemination of information?

A shoe retailer conducted a study to determine whether there is a difference in the number of pairs of shoes sold per day by stores according to the number of competitors within a 1-mile radius and the location of the store. The company researchers selected three types of stores for consideration in the study: stand-alone suburban stores, mall stores, and downtown stores. These stores vary in the numbers of competing stores within a 1-mile radius, which have been reduced to four categories: 0 competitors, 1 competitor, 2 competitors, and 3 or more competitors. Suppose the following data represent the number of pairs of shoes sold per day for each of these types of stores with the given number of competitors. Use α = 0.05 and analyze the data.

Choose any one of the following four statistical techniques. For your selected technique, create an original final exam problem, including any required data, which could be used to test BUS678 students' knowledge. Be sure that the problem you create is truly original - do not copy a problem from a textbook or other source. Solve the problem using SPSS and send select portions of your SPSS output.

a. ANOVA
b. Regression

c. Correlation

d. Chi-square

A study investigated the perception of corporate ethical values among individuals specializing in marketing. Using and the following data (higher scores indicate higher ethical values), test for significant differences in perception among the three groups of specialists.

Five sections of AMDS 8437 took a test in July. The scores are provided in the data file that accompanies this test, with sections identified as A, B, C, D, E.

a. Determine whether the mean grades in the sections might be equal; if they are not equal, determine which one(s) is different. Show all steps in the test(s) that you do. Use a 5% level of significance for your test.

b. What assumptions underlie the test(s) that you performed? Do you think the data satisfy those assumptions? Do you think the test is valid?

Are some unskilled office jobs viewed as having more status than others? Suppose a study is conducted in which eight unskilled, unemployed people are interviewed. The people are asked to rate each of the five positions on a scale from 1 to 10 to indicate the status of the position, with 10 denoting most status and 1 denoting least status. The resulting data are given here. Use α = 0.05 and analyze the data

Five sections of AMDS 8437 took a test in July. The scores are provided in the data file that accompanies this test, with sections identified as A, B, C, D, E.

a. Determine whether the mean grades in the sections might be equal; if they are not equal, determine which one(s) is different. Show all steps in the test(s) that you do. Use a 5% level of significance for your test.

b. What assumptions underlie the test(s) that you performed? Do you think the data satisfy those assumptions? Do you think the test is valid?

If the null hypothesis is rejected use the Scheffe' test when the sample sizes are unequal to test the differences between the means, and use the Tukey test when the sample sizes are equal. Test at the .05 significance level.

State the hypotheses and identify the claim, find the critical value(s), compute the test value, make the decision, summarize the results, and explain where the differences in means are.

The head of the English dept. wants to determine if the average number of students taking an English course differs depending upon the time of day that the court is being offered.

If the null hypothesis is rejected use the Scheffe' test when the sample sizes are unequal to test the differences between the means, and use the Tukey test when the sample sizes are equal. Test at the .05 significance level.

State the hypotheses and identify the claim, find the critical value(s), compute the test value, make the decision, summarize the results, and explain where the differences in means are.

The head of the English dept. wants to determine if the average number of students taking an English course differs depending upon the time of day that the court is being offered.

Number of grams of fiber per serving for a random sample of 3 different kinds of foods is listed. It there sufficient evidence at the 0.05 level of significance to conclude that there is a difference in mean fiber content among breakfast cereals, fruits, and vegetable?

Numbers (in thousands) of farms per state found in 3 sections of the country are listed below. Test the claim at a=.05 that the mean number of farms is the same across these 3 geographic divisions.

Lengths (in feet) of a random sample of suspension bridges in the US, Europe, and Asia are shown. At a=.05, is there sufficient evidence to conclude that there is a difference in mean lengths?

In a survey, 15% of Americans said they believe they'll eventually get cancer. In a random sample 80 Americans used in he survey, find these probabilities;

A) At least 6 people in the sample believe they will get cancer.

B) Fewer than 5 people in the sample believe they will get cancer.

The on-line access computer service industry is growing at an extraordinary rate. Current estimates suggest that only 45% of the home-based computers have access to on-line services. This number is expected to grow quickly over the next five years. Suppose 25 people with home-based computers were randomly and independently sampled. Find the probability that more than five but fewer than 8 currently have access to on-line services.

Whether a baseball player gets a hit in a single "at bat" follows a Binomial distribution with p = 0.4.

a.) What is the probability of at least 4 hits in 12 "at bats"?

b.) In 20 "at bats" what is the mean and standard deviation for the proportion of "at bats" that result in a hit?

30% of the general population donate their time and energy to working on community projects. If 15 people have been randomly sampled from a community and asked if they donated their time and energy to community projects. Let x be the number of them that do donate their time an energy to community projects. Find the Probability that more than 5 of the 15 do donate their time and energy to community projects.

A certain question on a test is answered correctly by 40% of the respondents. Find the probability that among the next 300 responses there will be at least 130 correct answers.

Use the binomial distribution.

a. If n = 4 and p =.10 find P{x = 3}.

b. If n=7 and p=.80 find P{x = 4}.

c. If n=10 and p=.60 find P{x>7}.

d. If n=12 and p=.45 find P [5<x<7}

The OVRTA reports that 74% of its buses are “on time”. If 200 buses are checked at random, the probability that there are more than 150 buses “on time” could be calculated by using the normal approximation to the binomial method

In Pittsburgh Pennsylvania, about 47% of the days in a year are cloudy. Find the mean, variance, and standard deviation for the number of cloudy days during the month of June. Hint: n=30 since there are 30 days in June.