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Hypothesis Testing

'Statistics for Managers' using Excel 5th edition: T F questions

True or False: The t distribution is used to develop a confidence interval estimate of the population mean when the population standard deviation is unknown. True or False: The confidence interval estimate of the population proportion is constructed around the sample proportion. True or False: The F test used for testing t

Hypothesis Testing -Number of Seniors Planning to Attend College

Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from this city reveals that 162 plan to attend college. Does this indicate that the percentage has increased from that of previous studies? Test at the 5%

Null and alternate hypothesis

1.A machine produces 5-inch nails. A sample of 12 nails was selected and their lengths determined. The results are as follows: 4.94 4.94 5.07 4.91 4.98 5.00 4.94 5.09 5.00 4.92 5.08 5.06 Assuming that a = 0.10, test the hypothesis that the population mean is equal to 5. ?State the null and alternate hypotheses ?&

Hypothesis testing: Coin flip example

A coin was flipped 100 times and came up heads 59 times and tails 41 times. The expected outcome was to land on heads or tails 50 times each. Do a hypothesis test to test the null that the percentage is equal to the expected as opposed to the alternative that it is greater or lesser or equal to the expected value, depending on

Sample Hypothesis Testing

Objective: Identify the formal hypothesis testing process. 1. If a null hypothesis is not rejected at the 0.10 level, it may be rejected at the 0.05 level. a. 0 True b. 0 False Objective: Perform a hypothesis test of one proportion. 2. The Roman Senate has become concerned about the loyalty of the army in Gaul com

Hypothesis Testing: Difference in the Means of the Two Groups

You are given the following data. Test the claim that there is a difference in the means of the two groups. Use = 0.01. Group A Group B x1 = 5 x2 = 7 s1 = 12 s2 = 18 n1 = 63 n2 = 86 · State the null and alternate hypotheses · Determine which test statistic applies, and calculat

The solution to Statistics: Hypothesis Testing

The pulse rates below were recorded over a 30-second time period, both before and after a physical fitness regimen. The data is shown below for 8 randomly selected participants. Is there sufficient evidence to conclude that a significant amount of improvement took place? Assume pulse rates are normally distributed. Test using =

Hypothesis Testing problem

A machine produces 5-inch nails. A sample of 12 nails was selected and their lengths determined. The results are as follows: 4.85 4.80 4.89 4.82 4.94 4.96 4.96 4.83 4.80 4.84 4.95 4.88 Assuming that = 0.10, test the hypothesis that the population mean is equal to 5. · State the null and alternate hypothe

Hypothesis Testing - Critical Value, P-value

In 2001, an estimated 78% of executives believed that age bias was a serious problem. In a 2004, 82% of the executives surveyed considered age bias a serious problem. The sample size for the 2004 study was not disclosed. Suppose 50 executives were surveyed. 1. At the 0.05 level of significance, use the 6-step critical value a

Find the P-value for the indicated hypothesis test

In a sample of 47 adults selected randomly from one town, it is found that 9 of them have been exposed to a particular strain of the flu. Find the P-value for a test of the claim that the proportion of all adults in the town that have been exposed to this strain of the flu is 8%.

F-test and confidence interval

Consider the following Hypothesis Testing: H0: δ1² = δ2² Ha: δ1² ≠ δ2² The sample size for sample 1 is 25, and for sample 2 are 21. The variance for sample 1 is 4.0 and for sample 2 is 8.2 a) at the confidence level of 0.98, what is your conclusion of this test? b) What is the confidence

Critical value/ p-value

The owner of a restaurant has just changed the delivery process in order to reduce the mean time between the order and completion of delivery from the current 25 minutes. In the past, the population standard deviation has been 6 minutes. A sample of 36 orders under the new delivery process results in a sample mean of 22.4 minu

Rejection Method and Interpret Results: Example Problem

A job placement director claims that the average starting salary for nurses is $24,000. A sample of 35 nurses has a mean of $23,450 and a standard deviation of $400. Is there enough evidence to reject the director's claim at alpha = 0.05? Use the rejection region method and provide an interpretation of the results.

Raw Data

Directions: Use the attached set of raw data to complete the following tasks. For tasks 1 through 4 please focus on New Mexico highway fatalities.. In task five you will be comparing New Mexico and U..S. highway fatalities. All work must be done by hand. You may use a calculator but only as an aid.. You must demonstrate tha

Statistics: 42 multiple choice questions

For all calculation questions (#25 - 42), provide detailed calculations. All confidence interval problems should be set-up in their proper format. For all hypothesis tests, you should state the null and alternative hypotheses that you are testing. For problems involving looking up values off a table, indicate which probability d

Hypothesis Testing of Variance & Sample size

Question 5 Use the traditional method to test the given hypothesis. Assume that the population is normally distributed and that the sample has been randomly selected A machine dispenses a liquid drug into bottles in such a way that the standard deviation of the contents is 81 milliliters. A new machine is tested on a sample

Statistics: Test Grocery store self checkout systems

Many grocery stores have installed self checkout systems. Below is the number of customers using the service for a sample of 15 days at the Wal-Mart in Boonton, 120 108 120 114 118 91 118 92 104 104 105 112 97 118 108 117 Is it reasonable to assume that the mean number of customers using self che

Statistics

Use n=25 for each problem where necessary. An accountant randomly selects (60+n) general accounts payable and examines them to determine whether they are correct. Six accounts contained errors. Construct a 98% confidence interval for the true proportion of general accounts payable that contain errors. Com

Minitab project

Please see the attachment. Instructions: ? Follow the directions for each problem. ? Use Minitab for all the calculations. ? The data set is available in contents page of D2L in the Final Exam module called fall 2009.MTW. ? Label each printout of your Minitab session according to the problem and part of that problem.

Dependent & Independent Variables, Hypothesis

NClinics, Inc. is a specialty e-tailer that sales clothing and accessories for nurses and operates 87 catalog Web sites on the Internet. Kevin Conn, Sales Director, feels that the style (color scheme, graphics, fonts, etc.) of a Web site may affect its sales. He chooses three levels of design style (neon, old world and sophist

Hypothesis Testing: Mean cost of raising a child

The US Department of Agriculture reports that the mean cost of raising a child from birth to age 2 in a rural area is $8,390. You believe that this value is incorrect, so you select a random sample of 900 children (age 2) and find that the mean cost is $8,275 with a standard deviation of $1,540. At α = 0.05, is there enough

Masterfoods targets proportion of red and brown candy colors

Masterfoods targets a proportion of 13% (0.13) for both the red and brown colors. Using the methods in Section 8.4, test the hypothesis (α = 0.05) that the population proportions of these two colors are equal. NOTE: These are NOT independent samples, but we will use this approach anyway to practice the method. This also

Likelihood of Fraud in a Furniture Retailer Fire

See attached data file. A wholesale furniture retailer stores in-stock items at a large warehouse located in Tampa, Florida. In early 1992, a fire destroyed the warehouse and all the furniture in it. After determining the fire was an accident, the retailer sought to recover costs by submitting a claim to its insurance company

Hypothesis Testing & Confidence Interval: yield of corn

Bushels of Corn Crop researchers plant 15 plots with a new variety of corn. The yields in bushels per acre are: 138.0 139.1 113.0 132.5 140.7 109.7 118.9 134.8 109.6 127.3 115.6 130.4 130.2 111.7 105.5 Assume that the standard deviation of the population is known to be σ = 10 bushels per acre QUESTIONS: 1. Wh