I am having trouble with some stats problems. Can you assist me? Thanks in advance The NPC, Inc. is a large mail order company that ships men's shirts all over the United States and Canada. They ship a large number of packages from their warehouse in Delta, Ohio. Their goal is to have 95 percent of the shipments delivered
Surveys have been widely used by politicians around the world as a way of monitoring the opinions of the electorate. Six months ago, a survey was undertaken to determine the degree of support for a national party leader. Of a sample of 1,100, 56% indicated that they would vote for this politician. This month, another survey of 8
An operations manager who supervises an assembly line has been experiencing problems with the sequencing of jobs. The problem is that bottlenecks are occurring because of the inconsistency of sequential operations. He decides to conduct an experiment wherein two different methods are used to complete the same task. He measure
This exercise is a "what if analysis" designed to determine what happens to the test statistics and interval estimates when elements of the statistical inference change. This can be solved manually or on Excel with Test statistics or Estimators workbook. Random samples from two normal populations produced the following statis
Use a 10% significance level. Every month a clothing store conducts an inventory and calculates the losses due to theft. The store would like to reduce these losses and is considering two methods. The first is to hire a security guard, and the second is to install cameras. To help decide which method to choose, they hired a
In random samples of 12 from each of two normal populations, we found the following statistics: Xbar1 = 74 S1= 18 Xbar2 = 71 S2 =16 a) Test with α= .05 to determine whether we can infer that the population means differ. b) Repeat part a increasing the standard deviations to S1= 210 and S2 =198. c) Describe what
A U.S. Department of Justice report included the claim that "in spouse murder cases, wife defendants were less likely to be convicted than husband defendants." Sample data consisted of 277 convictions among 318 husband defendants and 155 convictions among 222 wife defendants. Test the stated claim. Assume Aplha = 0.05. What are
Inspection of student data generated during pre/post treatment surveys shows that among 10 subjects, 7 had higher scores after an experimental treatment, 2 had lower scores, and 1 score did not change. Using the traditional method of hypothesis testing, we need to determine if the experimental course has any effect. Use an alpha
Assume that the random variable is normally distributed. A courier service advertises that its average delivery time is less than 6 hours for local deliveries. A random sample of times for 12 deliveries to an address across town was recorded. These data are shown here. Is this sufficient evidence to support the courier's adv
A machine that produces ball bearings is set so that the average diameter is .50 inch. A sample of 10 ball bearings was measured with the results shown here. Assuming that the standard deviation is .05 inch, can we conclude at the 5% significance level that the mean diameter is not .50 inch? .48 .50 .49 .52 .53 .48 .49 .47 .
A business student claims that on average an MBA student is required to prepare more than five cases per week. To examine the claim, a statistics professor asks a random sample of ten MBA students to report the number of cases they prepare weekly. The results are exhibited here. Can the professor conclude at the 5% significan
Calculate the value of the test statistic, set up the rejection region, determine the p-value, interpret the result, and draw the sampling distribution: H0 = µ = 100 H1 = µ does not equal 100 sigma = 10 n = 100 xbar = 100 alpha= .05
To see if young men ages 9 - 17 spend more or less than the average of $24.44 per shopping trip, the manager surveyed 33 young men and found the average amount spent was $22.67. The pop std us $3.70. At alpha 0.2, can it be concluded the average amount spent by the young men is not equal to $24.44 Perform appropriate hypoth
A survey by the national institute of health asked a random sample of young adults (aged 19 to 25), "Where do you live now? That is, where do you stay most often?" We earlier compared the proportions of men and women who lived with their parents. Here now is the full two-way table (omitting a few who refused to answer and one w
The color of a fabric depends on the dye used and also how the dye is applied. This matters to clothing manufacturers, who want the color of the fabric to be just right. The study discussed in the previous exercise went on to dye fabric made of ramie with the same "procion blue" dye applied in two different ways. Here are the
Publishing scientific papers online is fast, and the papers can be long. Publishing in a paper journal means that the paper will live forever in libraries. The British Medical Journal combines the two: it prints short and readable versions, with longer versions available online. Is this OK with authors? The journal asked a r
A random digit dialing telephone survey of 880 drivers asked, "Recalling the last ten traffic lights you drove through, how many of them were red when you entered the intersectinos?" Of the 880 respondents, 171 admitted that at least one light had been red. a)Give a 95% confidence interval for the proportion of all drivers who
As part of a study on transportation safety, the U.S. Department of Transportation collected data on the number of fatal accidents per 1000 licenses and the percentage of licensed drivers under the age of 21 in a sample of 42 cities. Data collected over a one-year period follow. Please see the attached file for the table.
In a study conducted to investigate browsing activity by shoppers, each shopper was initially classified as a nonbrowser, light browser, or heavy browser. For each shopper, the study obtained a measure to determine how comfortable the shopper was in a store. Higher scores indicate greater comfort. Suppose the following date we
1. A researcher demonstrated a correlation of r = 0.60 between teacher attire and student academic performance across 150 grade schools in her state. She concluded that encouraging teachers to be properly attired will increase academic performance. Do you agree or disagree with her conclusion? Why? 2. Give three real life or
In a two population test, when will you use independent samples? Provide an example and state the Null and the Alternative hypothesis for the examples in symbolic form.
In 1990, 5.8% of job applicants who were tested for drugs failed the test. At the 0.01 level, test the claim that the failure rate is now lower if a random sample of 1,520 current job applicants results in 58 failures. Does the result suggest that fewer job applicants now use drugs? Give the z score to 2 decimal places to, p(hat
The skid properties of a snow tire have been tested and a mean skid distance of 154 feet has been established for standardized conditions. A new, more expensive tire is developed, but tests on a sample of 17 new tires yield a mean skid distance of 148 feet with a standard deviation of 12 feet. Because of the cost involved, the n
Assume that a hypothesis test of the given claim will be conducted. The college Dean of Admissions claims that the times students require to earn a bachelors degree have a mean less than five years. Which equality/inequality (e.g., =, =<, etc.) would use in the Alternative Hypothesis?
Assume that a hypothesis test of the given claim will be conducted. The college Dean of Admissions claims that the times students require to earn a bachelors degree have a mean less than five years. Which equality/inequality (e.g., =, =<, etc.) would use in the Null Hypothesis?
It has been reported that 80% of taxpayers who are audited by the IRS end up paying more money in taxes. Assume that the auditors are randomly assigned cases and that one of the ways the IRS oversees its auditors is to monitor the percentage of cases that result in the tax payer paying more in taxes. A sample of 400 cases handl
Please explain the answers. Descriptions are in the file. 3. In order to test whether the mean IQ of employees in an organization is greater than 100, a sample of 35 employees is taken and the sample value of the computed test statistic, t_ = 3:5 The null and alternative hypotheses are: A) H0: X = 100; Ha: X 6= 100. B) H0:
The wages data set has a sample size of 100 people that were surveyed. Our error margin was .05. For the 47 females surveyed the mean wage was $24,451 per year with a standard deviation of $12,455 per year. For the 53 males surveyed the mean wage was $36,492 per year with a standard deviation of $18,447 per year. Check the clai
Discuss the link between the estimate and the parameter in the context of an hypothesis test. Be sure to reference the appropriate steps of the five step process in your response, based on the steps below: Step 1: State null and alternate hypothesis. Step 2: Select a level of significance Step 3: Identify the test statisti
Please see the attached file.