A study regarding the relationship between age and the amount of pressure sales personnel feel in relation to their jobs revealed the following sample information. At the .01 significance level, is there a relationship between job pressure and age? Degree of Job Pressure Age (years) Low Medium High Less than 25 20 18 22
Records indicate that the mean selling time of farm property is 90 days. Because of drought conditions they believe the mean is now greater. A survey of 100 farms sold recently revealed the mean selling was 94 days with a standard deviation of 22 days. At the .10 significance level, has there been an increase in selling time?
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
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
The use of cellular phones in automobiles has increased dramatically in the last few years. Of concern to traffic experts, as well as manufacturers of cellular phones, is the effect on accident rates. Is someone who is using a cellular phone more likely to be involved in a traffic accident? What is your conclusion from the follo
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
A recent study of the USA births showed the average birth weight of a male was 8 lbs.; the average weight of a female newborn was 7.4 lbs. I do not believe this to be true; hence, my research, based on a local Hawaiian hospital, showed: the average birth weight of a male was 7.5 lbs with a standard deviation of 2 lbs; the averag
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
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
In a randomized controlled trial in Kenya, insecticide treated bednets were tested as a way to reduce malaria. Among 343 infants who used the bednets , 15 developed malaria. Among 294 infants not using bednets, 27 developed malaria. Use a 0.01 significance level to test the claim that the incidence of malaria is lower for infant
The Genetics and IVF Institute conducted a clinical trial of the YSORT method designed to increase the probability of conceiving a boy. 51 babies were born to parents using the YSORT method, and 39 of them were boys. Sample data 0.01 significance level to test the claim that with this method, the probability of a baby being a bo
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%.
Question : Is there a statistically significant difference between the bowling averages of male nurses and those of businessmen, if last year's league play produced the following data: 10 male nurses averaged 180 with s=10 and 15 businessmen averaged 170 with s=10. Use level of significance of 5%.
Question : The mean score on a standardized psychology test is supposed to be 50. Believing that a group of psychologists will score higher, we test a random sample of 11 psychologists. Their mean score is 45 with s=3. Test at a level of significance of 1%.
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
NNIPS-II was a randomized study of 15,987 infants born alive to 43,559 women who received Vitamin A, Beta-carotene, or a placebo prior to and during pregnancy. (Investigators: Drs. Keith West, Joanne Katz, Parul Christian et al..) Infants were followed for up to 180 days after birth, until death (the event (outcome) being studie
Using the accompanying probability distribution, find the following values X P(x) 1 .25 2 .27 3 .05 4 .43 a) Mean b) Standard Deviation Assume that the cure rate for a certain drug is 20% and that 15 patients are tested with this drug. Find the following: a) Mean b) Standard Deviation c) P (exactl
Seven labs were used to measure the amount of chlorpeniramide malcate in tablets. The aim was to study the consistency between the labs and the variability of the measurement process. Each lab makes 10 measurements of a chemical mixture from ground tablets. The ANOVA table is given attached. a) Complete the table. What can yo
The advisors of an ecology club at a large college believes that the group consists of 10% freshman 20% sophomores 40% juniors and 30% seniors. The membership for the club this year consisted of 14 freshmen 19 sophomores 51 juniors and 16 seniors. At alpha= 0.1 test the advisors conjecture.
Part 1 Intelligence quotients (i.e. IQ's) as measured by one intelligence test are known to be normally distributed with a standard deviation of 16. Suppose a random sample of X denote the mean IQ score achieved on the test by 20 people take this intelligence test. Let this sample of 20 people. Suppose that, instead
A student conducted a study on the height and weight of adult males. She collected data from 40 adult males and found that average height is 68.34 inches with a standard deviation of 14.02 inches, and the average weight is 172.55 lbs. with a standard deviation of 26.33lbs. Based on the above values of the standard deviations,
Statistics Questions. See attached file for full problem description. 4. The attached table shows the data of 77 students on public or private school attendance in the elementary and high school grades. For example, 34 out of 77 students attended both public elementary and public high schools. Test at the 0.05 significanc
Discuss examples where you would use test of hypothesis at your personal or professional life, in your education or society for the following situations: (a) For two population means and discuss if the example would use large samples or small samples. (b) For two population proportions.