Do students at various colleges differ in how sociable they are? Twenty-five students were randomly selected from each of three colleges in a particular region and were asked to report on the amount of time they spent socializing each day with other students. The results for College X was a mean of 5 hours and an estimated popul
There are four auto body shops in a community and all claim to promptly serve customers. To check if there is any difference in service, customers are randomly selected from each repair shop and their waiting times in days are recorded. The output from a statistical software package is: Summary Groups Count Sum Aver
The MacBurger restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 sign
10. The manager of a computer software company wishes to study the number of hours senior executives spend at their desktop computers by type of industry. The manager selected a sample of five executives from each of three industries. At the .05 significance level, can she conclude there is a difference in the mean number of hou
Please see attached file for full problem description. 1) The bad debt ratio for a financial institution is defined to be the dollar value of loans defaulted divided by the total dollar value of all loans made. Suppose that a random sample of seven Ohio banks is selected and that the bad debt rations (written as percentages)
State DMV records indicate that of all vehicles undergoing emissions testing during the previous year, 70% passed on the first try. A random sample of 200 cars tested in a particular country during the current year yields 156 that passed on the initial test. Does this suggest that the true proportion for this country during the
1. For a specific confidence interval, the larger the sample size, the smaller the maximum error of estimate will be. T 2. An estimator is consistent if, as the sample size decreases, the value of the estimator approaches the value of the parameter estimated. ____ T/F 3. When we reject the null hypothesis, we are c
Find the critical t-value that corresponds to c = 0.95 and n = 16.
Choose a variable (such as number of daily admissions at a local theater or number of miles students have to commute daily to get to their college.) Before collecting the data, decide what a likely average might be, then complete the following: Write a brief statement of purpose of the study Define the population State the
List the steps involved in hypothesis testing using: a) the traditional/classical method; b) the probability-value method. Provide an example of each.
A sample size of 35 is used to test H0: m 65 vs. Ha: < 65. Given that = 63.5 and = 2.5, answer the following questions What is the computed value of the test statistic? What distribution does the test statistic have when the null hypothesis is true? Is the alternative hypothesis one-tailed or two-tailed? What is the p-v
A researcher claims that the average age of people who buy lottery tickets is 70. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 16. At alpha = 0.05 is there enough evidence to reject the researcher's claim? 49 63 90 52 22 80 72 56 82 56 24 46 70 74 70 61 65 71 39 74
Type I and Type II Errors In this scenario, (1) formulate both a null and (2) research hypothesis and give an example of both a (3) Type I and (4) Type II error. Scenario: You are Supervisor or Research for Doggie Heaven Biscuit Company. Your scientists have developed a new dog biscuit for the treatment of doggie breath. I
Can you tell me what are the advantages and limitations of applying nonparametric tests in solving business problems?
How would you apply the output from an Analysis of Variance (ANOVA) to solve a business problem? Please provide an example to show your reasoning.
Can you provide some pros and cons of using descriptive and inferential statistics to make managerial decisions.
There are 4 questions in word file and 1 question in excel file. Please show all work. Thanks 5. The manufacturer of the X-15 steel-belted radial truck tire claims that the mean mileage the tire can be driven before the tread wears out is 60,000 miles. The standard deviation of the mileage is 5,000 miles. The Crosset T
You must first determine which type of test this problem requires: Is it: A two sample independent sample tests: z or t depending upon the size of the samples (> or < 30 - both must be) or a two sample dependent tests: z or t depending upon the size of the samples (> or < 30 - both must be) - most of our work here is with t
Please see attached file for full problem description. Please help with the areas in red, thanks! Frequency Hypothesis Test #4) Does it seem to you that people tend to be absent more on some days of the week than on others? Recently, a major biotechnology firm collected data with the hope of determining whether or not it
A study was conducted in order to evaluate the hypothesis that tea consumption and premenstrual syndrome are associated. One hundred eighty- eight nursing students and 64 tea factory workers were given questionnaires. The prevalence of premenstrual syndrome was 39% among the nursing students and 77% among the tea factory workers
The average gasoline price of one of the major oil companies has been $2,25 per gallon. Recently, the company has undertaken several efficiency measures in order to reduce prices. Management is interested in determing whether their efficiency measures have actually reduced prices. That is, the alternative hypothesis is that
The McCollough Corporation, a producer of various kinds of batteries, has been producing D size batteries with a life expectancy of 87 hours. Due to an improved production process, the management believes that there has been an increase in the life expectancy of their D size batteries. A sample of 36 batteries showed an averag
A lathe is set to cut steel bars into lengths of 6 centimeters. The lathe is considered to be in perfect adjustment if the average length of the bars it cuts is equal to 6 centimeters. A sample of 25 bars is selected randomly, and the lengths are measured. It is determined that the average length of the bars in the sample is
You are a researcher who is interested in the effect of child care on the attachment which develops between an infant and a caregiver. You believe that infants in child care will be insecurely attached at 11 months after being in child care from 2 months of age, compared with infants who are cared for at home by their mother
1. A researcher wants to investigate the effects of prenatal alcohol on birth weight. A random sample of n = 16 pregnant rats is obtained. The mother rats are given daily doses of alcohol. At birth, one pup is selected from each litter to produce a sample of n = 16 newborn rats. The average weight for the sample is 15 grams. The
Trying to set up the analysis of a manufacturer of fluorescent light bulbs states that on the average, these light bulbs have a lifetime of 1600 hours. A sample of 100 bulbs was tested and the mean lifetime was 1570 hours with a standard deviation of 120 hours. Do these bulbs have a lifetime of 1600 hours? Test at .05 and .01
Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test s
The data in the attachment below represents the weight (mass) gained by 50 corn plants over a 3 week period. 10 plants each were given growth stimulators (labeled A, B, C, and D) and 10 plants were given no stimulator(that treatment is labeled S). Use the one-way anova capabilities of Excel to determine whether there ar
(a) state the decision rule, (b) compute the pooled estimate of the population variance, (c) compute the test statistic, (d) state your decision about the null hypothesis, and (e) estimate the p-value. The null and alternate hypotheses are: Ho: µ1 = µ2 Ha: µ1 ≠ µ2 Please use the five-step hyp
Suppose that the scores of architects on a particular creativity test are normally distributed. What percentage of architects have z scores (a) above .10 (b) below .10 (c)above .20 (d) below .20 (e) above 1.10 (f) below 1.10 (g) above -.10 (h) below -.10