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Hypothesis Testing


3. Auto Insurance Commissioner Auto insurance premiums in Massachusetts depend on the age of the driver and the driver's record but are not supposed to depend on gender. The state insurance commissioner wants to investigate whether there is any difference in the average premium that company A charges males and the average pre

Statistics Problem

The Atlanta Convention & Visitors Bureau just released a report on the percentage of available hotel rooms in Fulton County that were rented (occupied) in 2003. Looking over the report you note that room occupancy in March of 2003 was 77.6% (total rooms available is 14,800) and in December of 2003 it was 55.5% (of the 14,600 av

Testing Methods

I would like some help to practice further inferential statistics; and test for instance that the proportion of employees female satisfied by their job could be higher than the proportion of males Ho p1<or = p2 H1 p1>p2 And I would like to practice another test according your choice (chi-square, correlation or regression)

Test of hypothesis for proportions

Suppose prior elections in Louisiana indicated it is necessary for a candidate for governor to receive at least 80 percent of the vote in the northern part of the state to be elected. The incumbent governor is interested in assessing his chances of returning to office and conducts a survey of 2,000 registered voters residing i

I need help matching statistical symbols and definitions

I need your HELP with the matching of STATISTICAL SYMBOLS & DEFINITIONS DEFINITION 1.The average of the squared deviation scores from a distribution menas. 2. Midpoint in the distribution of numbers. 3. It has to do with the accuracy and precision of a measurement procedure. 4.Examines if an observed causal relationship

Statistics Variable Identification

A researcher has a data-set that includes the following variables measured on 50 small children. Given these variables: a) gender (male / female) b) age (continuous variable measured in months; ranges from 36 months to 72 months) c) preschool or daycare attendance (yes / no) d) height (continuous variable measured in

Hypothesis test..

An office equipment company advertises that it will deliver equipment within 15 days of purchase. A sample of 49 past deliveries is taken to test whether company's advertisement is valid. The delivery time for this sample was 16.2 days with a sample standard deviation of 5.6 days. Which of the following is correct * What is t

Research and Evaluation

1) A normal tomato will gain an average of 2 ounces per week during the growing season. A sample of 100 tomatoes is given a special hormone to increase their growth. The average weight gain of tomatoes in the sample was 3 ounces with a standard deviation of 1 ounce. Conduct a hypothesis test to determine if the hormone incre

Hypothesis Testing for the Proportion Parameter

Hypothesis Testing for the Proportion Parameter 1.) It is thought that the front cover and the nature of the first question on mail surveys influence the response rate. The article "The Impact of cover Design and First Question on Response Rates for a Mail Survey of Skydivers" (Leisure Science, 1991) tested this theory by exp

Testing of hypothesis of means

To test if the population mean is greater than 20 . We use z-test to test if the population mean is > 20 . We also use z-test to test if there is significant difference between means. See attached file for full problem description.

Descriptive Statistics of Hispanic Aid Support

(See attached file for full problem description and proper table representation) 1) Descriptive statistics: Please interpret this data a provide a description of the data represents. As you compare the means visually, what is your first impression about the difference in these means? Hispanic Women Hispanic Men Non- Hispa

Regression analysis: education and salary

Use the dataset "Employee data" (attached). Perform a regression that studies the impact of years of education on current salary. 1.(a) How may we interpret the coefficient for education? (b) Is the coefficient for education significant at the 5% level? (C ) What hypotheses are being tested by the t-statistic? (d) What

Statistics of Unabraded and Abraded Fabrics

Consider the accompanying data on breaking load (kg/25mm width) for various fabrics in both an unabraded condition and abraded condition. ("The effect of wet abrasive wear on the tensile properties of cotton and polyester-cotton fabrics," J.Testing and Evaluation, 1993: 84-93). Use the paired t-test, as did the authors of the ci

Hypothesis testing and P-Values

For which of the given P-values would the null hypothesis be rejected when performing a level .05 test? a) .001 b) .021 c) .078 d) .047 e) .148

Room Size and BTUs

Based on the question and the bogus raw data, provide a complete analysis. Be sure to include statdisk or excel: Does the room size play an important factor in choosing the correct BTU's? A general rule is that 5,000 to 6,000 Btu/hrs. models cool rooms 100 to 300 square feet; 7,000 to 8,200 Btu/hr. models cool rooms 250 to 55

Statistics Concepts and Calculations

16-22. The following sample data were obtained from three populations where the variances were not equal, and you wish to compare the populations. Sample 1 Sample 2 Sample 3 21 15 38 29 17 40 35 22 44 45 27 51 56 31 53 71 1. State the null hypothesis. 2. Using the .01 level of risk, state the decision rule. 3. C

Significance testing in 5 different situations

1. Suppose you want to test the claim that the population mean(u) is < or equal to 25.6. Given a sample size of n=44 and a level of significance of 0.05, when should you reject the null hypothesis? 2. Given the null hypothesis: population mean = 25 and the alternative hypothesis population mean not equal to 25, and P=0.041

One-Tailed Tests for Population Standard Deviation of Mean Income of Teachers

Past records suggest that the mean annual income, u1, of teachers in state of Utah is greater than or equal to the mean annual income, u2, of teachers in Oregon. In a current study, a random sample of 10 teachers from Utah and an independent random sample of 10 teachers from Oregon have been asked to report their mean annual inc

6 Hypothesis Testing Questions

Problem 14.3 The marketing manager of a large supermarket chain would like to determine the effect of shelf space on the sales of pet food. A random sample of 12 equal-sized stores is selected, with the following results: (see attachment for clearer tables) Store Shelf Space X (Feet) Weekly Sales Y (Hundreds of Dollars

Statistics, Research and Evaluation

1. Determine what would happen to your critical value (Z) if you were to change the level of significance (a) from .05 to .1 in a two tailed hypothesis test. 2. Why would the critical value change in the way you predict? 3. What does this suggest about the trade offs between Type 1 and Type II errors? Please give s

Hypothesis Test: Two-tailed Test of Difference Between Means

According to the historical data, the life expectancy in Argentina is equal to the life expectancy in Bolivia. A new study has been made to see whether this has changed. Records of 295 individuals from Argentina who died recently are selected at random. The 295 individuals lived an average of 74.8 years with a standard deviat

Significance Level: Time Spent at Desktop

10. The manager of a computer software company wishes to study the number of hours senior executives spend at their desktop computers by type of industry. The manager selected a sample of five executives from each of three industries. At the .05 significance level, can she conclude there is a difference in the mean number of hou

Statistics problems dealing with probability

1. All Seasons Plumbing has two service trucks which frequently break down. If the probability the first truck is available is .75, the probability the second truck is available is .50, and the probability that both trucks are available is .30, what is the probability neither truck is available? 2. Textbook authors and publi

Testing proportions

The manufacturer of Feel Better aspirin advertises that 60% of pediatricians recommend Feel Better for children under twelve. Safe and Sound, a rival manufacturer, surveyed 650 pediatricians and found that only 357 of them recommended Feel Better for children under twelve. Safe and Sound now claims that Feel Better's advertising

Hypothesis testing

A researcher claims that the average age of a woman before he has her first child is now greater than it was in 1990. In 1990, that average age was 26.4 years. She obtains a random sample of 40 women who all recently gave birth to their first child, and calculates their mean age to be 27.1 years. From another recent study, she

Testing a hypothesis: emergency response

Suppose a candidate running for sheriff claims that she will reduce the average speed of emergency response to less than 3o minutes. (30 minutes is thought to be the average response time with the current sheriff,) There are no past records so the actual standard deviation of such response times cannot be determined. Thanks to t

Hypothesis testing

The NCAA requires colleges to report the graduation rates of their athletes. At one large university 70.7% of all students who entered between 1989 and 1991 graduated within 6 years. 95 of the 147 students who entered with athletic scholarships graduated. Consider these 95 as a sample of the athletes who will be admitted under p

Research and Evaluation

What are some of the ethical issues we encounter in using hypothesis testing? How might we discover if a researcher has compromised ethics in reporting hypothesis testing results? When and how would we use hypothesis testing at our place of employment, or in politics?