### Measures of variability with inferential statistics

Explain why measures of variability are essential to inferential statistics.

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Explain why measures of variability are essential to inferential statistics.

Perform hypothesis testing on one variable's data(choose either the intrinsic or extrinsic Job Satisfaction)using 25 as our data set number. Perform a t-test by formulating a null and an alternative statement choosing an acceptable significance value, determining the appropriate critical value, selecting the test statistic and

STATISTICS Tasks: ? Decide on an issue that you wish to investigate and obtain the sample data that you will use. ? Decide on 5 questions (in everyday English) that you wish to answer. Note: At this stage, do not try to answer these questions. ? For each quantitative variable use Excel to analyze your data by o p

Chrysler Corporation agrees to allow you to randomly select 40 of its new Dodge Caravans to test the highway mileage. Chrysler claims that the caravans get 28mpg on the highway. Your results show a mean of 26.7 and a standard deviation of 4.2. You support Chrysler's claim. 1. Show why you support Chrysler's claim by listing t

The team determined that to confirm the validity of their screening experiment they should compare the test score results for some students that were at both the high setting and low setting within the last three years. This would allow them to compare the impact of the factors for individual students. What I need to fi

Please see the attachment.

The Non-Profit Times conducted a random sample of 126 U.S. non-profit companies at the beginning of 2005. The results reported that the average salary of an executive director of a nonprofit was $92,411 per year with a sample standard deviation of $25,326. A research team from a competing newspaper, which was skeptical of thes

1. Periodically, Merrill Lynch customers are asked to evaluate Merrill Lynch financial consultants and services (2000 Merrill Lynch Client Satisfaction Survey). Higher ratings on the client satisfaction survey indicate better services, with 7 the maximum service rating. Independent samples of service ratings for two financial co

Birdie Golf Equipment Birdie Golf Equipment is a major manufacturer of golf equipment. Management believes that that Birdies market share could be increased with the introduction of a new cut-resistant, longer-lasting golf ball. Therefore, the research group at Birdie has been investigating a new golf ball coating designed

23. Microwave Repair Costs A microwave oven repairer says that the mean repair cost for damaged microwave ovens is less than $100. You work for the repairer and want to test this claim. You find that a random sample of five microwave ovens has a mean repair cost of $75 and a standard deviation of $12.50. At a = 0.01,do you have

What are the steps in formal hypothesis testing? Make at least two explanatory comments about each step.

4. A survey was conducted to compare the proportion of male and female adults, 25 years or older, who have completed four or more years of college. It was found that among 350 females, 100 completed four or more years of college, and among 400 males, 115 completed four or more years of college. At sigma = 0.02, is the proportion

What test of differences is appropriate in each of the following situations and why ? (a) Average campaign contributions of Democrats, Republicans, and Independents are to be compared. (b) Managers and supervisors have responded "yes," "no," or "not sure" to an attitude question. Their answers are to be compared. (c) On

Formulate a hypothesis statement regarding the research issue. Perform the five-step hypothesis test on the data. Explain which non parametric test you used to analyze your data and why you choose that test. Interpret the result of your test. My null hypothesis is the salary of baseball players does not depend on the

Please help with the following problem. Question: A new car is designed to run a mean of at least 50 000 kilometers before its first tune-up. Tests with 30 cars show a sample mean of 49 500 kilometers and a sample standard deviation of 1000 kilometers. a. Develop the null and alternative hypotheses most appropriate fo

A candidate must gather at least 8,000 valid signatures on a petition before the deadline in order to run in an election. One candidate turns in 10,000 signatures right before the deadline, but it's always expected that some percentage of them are invalid. Elections officials take the random sample of 100 signatures and thorough

a. State the hypotheses and identify the claim b. Find the critical value c. Compute the test value d. Make the decision e. summarize the results and explain where the differences in the mean are Question # 1 Number of State Parks The number of state parks found in selected states in three different regions of the country

1. An appropriate 95% confidence interval for mu has been calculated as (- 0.73, 1.92) based on n = 15 observations from a population with a normal distribution. The hypotheses of interest are H0 : mu = 0 versus Ha: mu <> 0. Based on this confidence interval ... 3. An analyst, using a random sample of n = 500 families, obtai

II Solve each problem below. Be sure to show essential calculations. 11. The following statements refer to the alternate hypothesis. In the space provided, in symbolic form using H0, and H1 , write the null and alternate hypothesis. a. The mean pulse of lawyers is different from 90 beats per minute. H0: ____________________

You are trying to get an important new customer to buy a product that you produce. Their decision to buy depends on the speed at which you can produce the product once they have placed the order. Currently it takes you 70 hours on average to produce the product with a standard deviation of 8 hours. From historical data you have

An automobile manufacturer stated that it would be willing ot mass produce electrically powered cares if more than 30% of potential buyers indicate they would purchase the newly designed electric cars. In a sample of 500 potential buyers, 160 indicated they would buy such a product. Should the manufacturer produce the new elec

A sample of 64 account balances from a credit card company showed an average balance of $1,040. A previously determined population standard deviation is $200. Test to determine if the mean of all account balances is significantly different from $1,000. Use a 0.05 level of significance. (may use traditional or p-value method)

11. In order to test to see if there is any significant difference in the mean number of units produced per week by each of three production methods, the following data were collected: Method I Method II Method III 182 170 160 170 192 156 185 190 179 a. Compute the overall sample mean . b.

52. The president of the American Insurance Institute wants to compare the yearly costs of auto insurance offered by two leading companies. He selects a sample of 15 families, some with only a single insured driver, others with several teenage drivers, and pays each family a stipend to contact the two companies and ask for a p

31. A new weight-watching company, Weight Reducers International, advertises that those who join will lose, on the average, 10 pounds the first two weeks with a standard deviation of 2.8 pounds. A random sample of 50 people who joined the new weight reduction program revealed the mean loss to be 9 pounds. At the .05 level of sig

Candies manufactured by Cherrie Chocolate Candies Co, are supposed to weigh at least 2.00 ounces. A sample of 100 candies yields the following results. Sample mean: 1.98 ounces Sample standard deviation: 0.10 ounces Does the sample data present sufficient evidence to conclude that the average weight is in fact less than 2.0

The president of Crooked Arrow National Bank wants to determine whether more than 60% of the banks loans are made to persons residing in Crooked Arrow. A random sample of 500 loans is selected with 320 being made to persons residing in Crooked Arrow. a. Does the sample data provide evidence to conclude the more than 60% of th

Please refer attached file for the tables. 1. A stock analyst wants to determine whether there is a difference in the mean rate of return for three types of stock: utility, retail, and banking stocks. The following sample information is collected. a. Using the 0.05 level of significance, is there a difference in the mean r

1. A manufacturing company measures the weight of boxes before shipping them to the customers. If the box weights have a population mean and standard deviation of 90 lbs. and 24 lbs. respectively, then based on a sample size of 36 boxes, the probability that the average weight of the boxes will: Be less than 84 lbs. is: a.

It's almost decision time, and the stakes are huge. With astronomical TV advertising costs per minute of airtime, it's been worthwhile to do some preliminary work so that nothing is wasted. In particular, you've been helping manage an effort to produce 22 ads for a personal hygiene product, even though only just a few will ever