For several decades, it was a common practice in Southern California for houses to be built with pools in the backyard (as any airplane flight that ends at a Southern California airport will reveal). However, that practice may be changing, possibly because of the recent demand for landscaped homes, which experts believe help red
A random sample of 51 observations was selected from a normally distributed population. The sample mean was xbar = 88.6, and the sample variance was s2 = 38.2. Does the sample show sufficient reason to conclude that the population standard deviation is not equal to 8 at the 0.05 level of significance? Use the p-value method.
An insurance company states that 90% of its claims are settled within 5 weeks. A consumer group selected a random sample of 100 of the company's claims and found 75 of the claims were settled within 5 weeks. Is there enough evidence to support the consumer group's claim that fewer than 90% of the claims were settled within 5 we
Many cities have adopted HOV High Occupancy Lanes to speed up commuter traffic to downtown business districts. Planning for Metro Transportation District has depended on a well-established average of 3.4 passengers per HOV. But a summer intern notes that because many firms are sponsoring van pools, the average number of passenge
If given the following hypothesis: Ho: the mean is less than or equal to 10 H1: the mean is greater than 10 For a random sample of 10 observations, the sample mean was 12 and the sample standard deviation 3. Using the .05 significance level: 1. State the decision rule. 2. Compute the value of the test statistic
1. A survey of 120 high school students shows that 39 of them work over 20 hours per week during the school year. Does it demonstrate the conjecture that more than 25% of the high school students work over 20 hours per week during the school year? ( Answer by calculating the P - value.) 2. Each year an insurance company revie
Using the same data set used the previous paper (see attached), please prepare a paper describing a new hypothesis test using a different statistic (large sample size,small sample, means and /or proportions, one and two-tailed tests) and performing the five-step hypothesis test again on that data. Formulate a new hypothesis
How tall are college hockey players? The average height has been 68.3 inches. A random sample of 14 hockey players gave a mean height of 69.1 inches. We may assume that x has a normal distribution with mu = 0.9 inch. Does this indicate that the population mean height is different from 68.3 inches? Use 5% level of significan
The hypothesis is that the Southerners are less educated than the population at large. Now keep in mind that because this is a one tailed test, you can interchange the null and the alternate hypothesis. Also, null is usually given the benefit of the doubt. Thus the '=' sign goes with the null. In this case because we have to pro
Recently the national average yield on municipal bonds has been μ = 4.19%. A random sample of 16 Arizona municipal bonds gave an average yield of 5.11% with a sample standard deviation s = 1.15%. Does this indicate that the population mean yield for all Arizona municipal bonds is greater than the national average? Use &#
Young married couples are asked to complete a "Love & Respect" survey (higher scores indicate positive attitude) before and after completion of a six week marriage enrichment course taken through their church. A composite respect score for the couple is shown below. a. Conduct the appropriate test to determine if there was a s
Time to complete complex math problems while listening to music was investigated using 16 high school students. Students were matched on their math gpa, then randomly assigned to either the Country Western music group or the Classical music group. a. Conduct the appropriate analysis to determine if there was an effect of t
Test of product quality using human inspectors can lead to serious inspection error problems. To evaluate the performance of inspectors in a new company, a quality manager had a sample of 12 novice inspectors evaluate 200 finished products. The same 200 items were evaluated by 12 experienced inspectors. The quality of each item
2) Researchers at the University of South Alabama compared the attitudes of male college students toward their fathers with their attitudes toward their mothers. Each of a sample of 13 males was asked to complete the following statement about of their parents: My relationship with my father (mother) can best be described as: (1
A study report in Journal of Small Business Management (1977) concluded that self-employed individuals experience higher job stress than individuals who are not self employed. In this study job stress was assessed with a 15-item scale designed to measure various aspects of ambiguity and role conflict. Rating for each of the 15 i
1. Analyze data analysis to determine whether the appropriate statistical procedure were used to analyze data. 2. Provide an explanation of the meaning of the results of each study based upon the findings from the statistical tests. Article attached -- it's about differences in health care in people before and after they
The purchase of a coin-operated laundry is being considered by a potential entrepreneur. The present owner claims that over the past 5 years the average daily revenue has been $675 with a standard deviation of $75. A sample of 30 selected days reveals a daily average revenue of $625. a. State the null and alternative hypoth
In a word problem, how does one know whether to use a one-tailed test or a two-tailed test? What are some of the words that form clues? How does one know what is a population parameter and a test statistic?
Null Hypothesis and Statistical procedures. 1. You are in charge of the training program for pilots transitioning from fixed wing to rotary wings aircraft. You are considering the purchase of a simulator for initial training, but you are unsure if the quality of the simulator training will be worth the expenditure. You have a
Refer to the data in the table (attached) that lists SAT scores before and after the random sample of 10 students took a preparatory course. Is there sufficient evidence to conclude that the preparatory course is effective in raising scores? Use a 0.05 significance level.
The management of White Industries is considering a new method of assembling its golf cart The present method requires 42.3 minutes, on the average to assemble a cart. The mean assembly time for a random sample of 24 carts using the new method was 40.6 minutes and the standard deviation of the sample was 2.7 minutes. Using the
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 Truck Company bought 48 tires and found that the mean mileage for their trucks is 59,500 miles. Is Crosset's
A physician's health study of the effectiveness of aspirin in the reduction of heart attacks was begun in 1982 and completed in 1987. Of 11,037 male medical doctors in the United States who took one 325 mg buffered aspirin tablet every other day, 104 suffered heart attacks during the five-year period of the study. Of 11,034 male
Experience raising New Jersey Red chickens revealed the mean weight of the chickens at five months is 4.35 pounds. The weights follow the normal distribution. In an effort to increase their weight, a special additive is added to the chicken feed. The subsequent weights of a sample of five-month-old chickens were (in pounds):
The management at Black Angus is considering hiring 8 additional servers. Currently 12 servers are serving 4 tables each per hour. Servers make $11.25 on overtime per hour. Servers are having to work 2 hours of overtime per day 4 days a week. Would hiring 8 additional servers 4 days a week at $7.50 per hour working 6 hour sh
(Q: 12) Suppose you want to develop a model to predict assessed value based on heating area. A sample of 15 single-family houses is selected in a city. The assessed value (in thousands of dollars) and the heating area of the houses (in thousands of square feet) are recorded with the following results: House Assessed Valu
Discuss the null hypothesis. How is it framed? What is the alternate hypothesis? How does it relate to the null hypothesis? Can you have possible outcomes not embraced by the null or alternate hypotheses?
1. 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 0.05 s
#4.3 Suggest applications of nonparametric methods to solving business related problems. Describe the example. How are you or could you use nonparametric methods to solve business related problems?
Over a period of months an adult male patient has taken eight blood tests for uric acid. The mean concentration iswas x with a line over it =5.35 mg/dl. The distribution of uric acid for the health adult male can be assumed to be normal with the standard deviation of 1.85 mgdl. a. Find a 95% confidence interval for the popula