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Hypothesis Testing

Hypothesis Test

A manufacturer is interested in determining whether it can claim that the boxes of detergent it sells contain, on average, more than 500 grams of detergent. From past experience the manufacturer knows that the amount of detergent in the boxes is approximately normally distributed. The firm selects a random sample of 100 boxes an

Performance of First Grade Students vs. National Norm

In comparing the performance of first-grade students in his district with the national norm of 100 on a widely used IQ test, the results for a random sample of his first graders lead him to retain Ho: ? = 100 (? = .01) for his population. He concludes, 'My research proves that the average first grader in our district falls right

Method process for null hypothesis

Be sure to clearly state your decision on the null hypothesis 1: 9:31: At Oxnard University, a sample of 25 senior accounting majors showed a mean cumulative GPA of 3.25 with a standard deviation of 0.10. At α = .05 in a two-tailed test, does this differ significantly from 3.20 (the mean GPA for all business school sen

Statistics

Exercise 1 One step in the manufacture of a certain metal clamp involves the drilling of four holes. In a sample of 150 clamps, the average time needed to complete this step was 72 seconds and the standard deviation was 10 seconds. (a) Find the probability that the average time to complete the step is between 65 and 74 sec

Data Analysis

For the following data: Fiscal Year GDP-US ($ billion) Total Spending ($ billion) 1996 7838.5 2719.43 1997 8332.4 2813.59 1998 8793.5 2923.39 1999 9353.5 3053.51 2000 9951.5 3240.18 2001 10286.2 3434.00 2002 10642.3 3697.75 2003 11142.1 3930.63 2004 11867.8 4131.92 2005 12638.4 4397.34 2006 13398.9 4698.23 2007 14

Molar Heat of Fusion of Water; Difference in Diesel Truck Fuel

Exercise 1 Two methods for measuring the molar heat of fusion of water are being compared. Ten measurements made by method A have a mean of 6.02 kilojoules per mole (kJ/mol) with a standard deviation of 0.02 (kJ/mol). Five measurements made by method B have a mean of 6.00 kJ/mol and a standard deviation of 0.01 kJ/mol. a)

5 Step Hypothesis Test

Test the hypothesis that the population average income is greater than $55,000 using 5-step hypothesis test. Given: Sample Mean = $55,450, Sample Standard Deviation = $2,500 Sample Size =121, Significance Level, alpha = 5% State your conclusion in statistical terms and in conversational English. Compute the p-value

5 Step Hypothesis Test

Test the null hypothesis that a population mean is 50 against the alternate hypothesis that the mean is not 50. The data is of ratio level. A sample of 400 showed a sample mean of 51.5 and a sample standard deviation of 10. Use the full, formal hypothesis testing format. What "model" should be used and why?

Inference: Mean study time for first year university students

A class survey in a large class for first year college students asked "About how many minutes do you study on a typical weeknight?" The mean response of the 269 students was x (bar over x) = 137 minutes. Suppose that we know that the study time follows a Normal distribution with standard deviation = 65 minutes in the populatio

Bem Sex-Role Inventory personality test for hotel managers

Successful hotel managers must have personality characteristics often thought of as feminine as well as those often thought of as masculine. The Bem Sex-Role Inventory (BSRI) is a personality test that gives separate ratings for female and male stereotypes, both on a scale of 1 to 7. A sample of 148 male general managers of th

Statistics of Predicting Runs Scored in Baseball

See attached data file. Predicting runs scored in baseball. Statistician Scott Berry built a multiple regression model for predicting total number of runs scored by a Major League Baseball team during a season. Using data on all teams over a 9-year period (a sample of n = 234), the results in the attached table were obtai

Hypothesis Testing of Population Proportion..

Chicken Delight claims that 86 percent of its orders are delivered within 10 minutes of the time the order is placed. A sample of 80 orders revealed that 81 percent were delivered within the promised time. At the .10 significance level, can we conclude that less than 86 percent of the orders are delivered in less than 10 minutes

American Pet Food Dealers Association Data

According to a study by the American Pet Food Dealers Association, 42 percent of U.S. households own pets. A report is being prepared for an editorial in the San Francisco Chronicle. As a part of the editorial a random sample of 265 households showed 175 own pets. Does this data disagree with the Pet Food Dealers Association dat

Hypothesis Testing of Mean.

A researcher claims that the average age of people who buy lottery tickets is 61. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 9. At a = 0.05 is there enough evidence to reject the researcher's claim? Show all work. 65 63 75 52 22 80 72 56 82 56 24

Hypothesis Testing: Types of Tests and Errors

Please help with the following questions. What is a one tail test? A two tail test? When are they used? What is a type I error? A type II error? In the hypotheses: Ho: A new auto engine gets the same mpg as an older version Ha: A new auto engine gets more mpg than an older version

T-tests comparing treatment one to treatment two

1. The following data are from an independent-measures experiment comparing two treatment conditions. Do these data indicate a significant difference between the treatments Treatment one: 13 9 7 11 Treatment two: 9 5 5 9 2. A sample of freshmen takes a reading comprehension test and their scores are summarized b

Statistics

FLOWER PRODUCTION OF DWARF SCHRUBS Dwarf shrubs are popular with model home landscapers. Stetson University researchers conducted an experiement to determine the effects of fire on the schrub's growth. Twelve experimental plots of land were selected in a pasture where the shrub is abundant. Within each plot, three dwarf sh

Massachusett's top public schools failed meet improvement goals

In the 1990s, Massachusetts introduced the mandatory student testing program Massachusetts Comprehensive Assessment System (MCAS). According to the Massachusetts Department of Education, "based on 1998 MCAS test scores, all schools were placed in one of six baseline categories, Very High, High, Moderate, Low, Very Low or Critica

5 Statistics problems: Mean bounce height, waiting time, Epox glue, paint additive

1. A machine is set produce tennis balls so the mean bounce is 36 inches when the ball is dropped from a platform of a certain height. The productions supervisor suspects that the mean bounce has changed and is less than 36 inches. As an experiment a sample of 12 balls was dropped from the platform and the mean height of the bou

Statistics: Hypothesis Testing Problem

1. The mean construction time for a standard two-car garage by Arrowhead Construction Company is 3.5 days. The time for the construction process follows the normal distribution. The construction process is modified through the use of 'precut and assembled roof trusses' rather than onsite construction of roof rafters. This should

Statistics: Hypothesis testing for salaries of postgraduates

Salaries of postgraduates Refer to "Economics of Education Review" (Vol. 21, 2002) study of the relationship between education level and earnings, Excercise 6.31 (p. 336). A National Adult Literay Survey revealed that males with a postgraduate degree had a sample mean salary of of $61,340 (with standard error = $2,185), whil

Hypotheses: asthma attack; heart failure patients; ICU days

See the attached file for clarity in the tables. 1. It is suspected that high pollution levels (measured by number of particulates found in the air) increase the levels of asthma attacks. A researcher collects data on50 people who experienced an asthma attack during the course of one year. For each person the number of part

Purchasing Manager Tests Lifetimes of Light Bulbs for LCD Projectors

A purchasing manager for a large university is investigating which brand of LCD projector to purchase to equip "smart" classrooms. Of major concern is the longevity of the light bulbs used in the projectors. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, and wishes to determi

Mean Waste Generated

As part of your work for an environmental awareness group, you want to test the claim that the mean waste generated by adults in the country is more than three pounds per person per day. In a random sample of 11 adults in the country, you find that the mean waste generated per person per day is 3.3 pounds and the standard deviat

Test Random Sample of 100 Observers from a Binomial Population

Suppose a random sample of 100 observers from a binomial population gives a value of p* = .63 and you wish to test the null hypothesis that the population parameter p is equal to .70 against the alternative hypothesis that p is less than .70. a) Noting that p* = .63, what does your intuition tell you? Does the value of p* ap