The breaking strengths of cables have a mean of 1825 lbs and a standard deviation of 65 lbs. The company claims that there is an improvement in breaking strength. To evaluate this claim, 16 cables are randomly chosen and tested -- their mean breaking strength is 1859 lbs. Can we support, at the 0.05 significance level, the cl
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
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
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
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
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
Null Hypothesis and Statistical procedures for wing to rotary wings aircraft data. Null Hypothesis, Alternative Hypothesis, Significance Level, Critical Value, P value are included in the solution.
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
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
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?
#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
1. The scores on a placement test given to college freshmen for the past five years are approximately normally distributed with a mean µ = 74 and a variance ơ ² = 8. Would you still consider ơ ² = 8 to be a valid value of the variance if a random sample of 20 students who take this placement test this year obtain
Is there sufficient evidence to conclude that there is a significant difference between the percentage of men and the percentage of women who fear flying?
The lives of many people are affected by a fear that prevents them from flying. The Marist Institute for Public Opinion conducted a poll of 1014 adults, 48%of whom were men. The results reported in USA Today showed that 12% of men and 33% of the women fear flying. a) Is there sufficient evidence to conclude that there is a s
Item 1: One- tail (upper): Explain the problem you would test for (make up numbers) and state the hypotheses in both numeric and narrative form. Explain why this would be a upper tailed test. Do no calculations or list any formulas. Item 2: One-tail (lower) Explain the problem you would test for (make up numbers) and state th
For many years, TV executives used the guideline that 30 percent of the audiences were watching each of the prime-time networks and the 10 percent were watching cable stations on a weekday night. A random sample of 500 viewers in the Tampa - St. Petersburg, Florida area last Monday night showed that 165 homes were turned in to t
1. As reported by the College Entrance Examination Board in National College-Bound Senior, the mean verbal score on the Scholastic Assessment Test (SAT) in 1998 was 505 points out of a possible 800. A random sample of 25 verbal scores for last year yielded the following data. 421 571 427 453 390 566 435 460 575 633 4
1. Ten years ago, the mean age of all juveniles held in public custody was 16.0 years, as reported by the U.S. Office of Juvenile Justice and Delinquency Prevention in Children in Custody. The ages of a random sample of juveniles currently being held in public custody are to be used to decide whether this year's mean age of all
Solve using Goal Seek: The Palace Hotel believes it's customers may be waiting too long for room service. The hotel operations manager knows that the time for room service orders is normally distributed and he sampled 10 room service orders during a 3-day period and timed each ( in minutes) as follows: 23 23 15 1
2. Over the past five years, the average amount of sales invoices for Swanson Co. is $120. A random sample of 12 sales invoices from this month averaged $112.85 with a standard deviation of $20.80. Conduct test to find out if average sales invoice this month differs from the historical data. Level of significance a = .05
Statistics Research and Evaluations Questions. 1. A test of hypothesis is always about: a. population parameter b. sample statistic c. a test statistic 2. A critical value is the value a. calculated from sample data b. determined from a table (e.g., normal distribution table or other such table
1. A few years ago, a cola manufacturer invited consumers to take a blind taste test. Consumers were asked to determine which of two sodas (brand 1-the manufacturer's own soda, or brand 2 -the competitor's soda) they preferred. The manufacturer was interested in determining what factors played a role in people's taste preferen
Construct a 95% confidence interval estimate of the difference between the percentage of men and the percentage of women who fear flying.
The lives of many people are affected by a fear that prevents them from flying. An institute for public opinion conducted a poll of 1014 adults, 48%of whom were men. The results reported in USAToday showed 12 % of the men and 33% of the women fear flying. 1. Construct a 95% confidence interval estimate of the difference betw
Question 1: The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude, and study habits of college students. Scores range from 0 to 200 and follow (approximately) a normal distribution with mean 115 and standard deviation 25. You suspect that incoming freshmen have a mean u
Question: To test whether or not there is a difference between the mean grade point average of male math majors and female math majors at a certain university, 2 random samples were gathered. For the 35 males, we find that x1= 3.1 with s1=0.2. For the females, x2=3.2 with s2=0.15. Test at a level of significance of 1%.