Share
Explore BrainMass

Hypothesis Testing

Research Methods / Statistics: 3. Four experimenters investigated the number of items recalled in a study of short-term memory when comparing some 25 year-old participants (Y) with some 65 year-old participants (O). (Use a two-tailed test.) a) Analyze the data as an independent samples design. b) Analyze the same data set as a matched pairs design.

See attachment for complete question. 3 Four experimenters investigated the number of items recalled in a study of short-term memory when comparing some 25 year-old participants (Y) with some 65 year-old participants (O). (Use a two-tailed test.) For this question you will be assigned data from one of these exp

Psychology Research Methods / Stats - Analyze the Data

2. Pigeons were trained to peck to obtain food. During extinction, one group of 21 pigeons was given a drug that inhibits the protein metabolism necessary for memory, while another group of 21 pigeons was not. The rate of pecking was then analyzed (use a one-tailed test). Does the drug increase the pigeons' pecking behaviour?

Design and Analysis of an Experiment Question

From time to time, one branch office of a company must make shipments to a certain branch office in another state. There are three package delivery services between the two cities where the branch offices are located. Since the price structures for the three delivery services are quite similar, the company wants to compare the d

Health Study on Aspirin

US physicians, health study consisted of two randomized clinical trails in one. the first tested the hypothesis that 345 milligrams of aspirin taken every other day reduces mortality from cardiovascular disease. The second tested whether 50 mg B-carotene taken on alternate days decreases the incidence of cancer. 261,248 male phy

Inference

1. A 4-day work week ensure that employees will have one more day that need not be spent at work. One possible result is a reduction in the average number of person leave days taken by employees on a 4-day work schedule. Do the data indicate that this is the case? use the p-value approach in testing to reach your conclusion.

Test of hypothesis, p value, confidence interval, linear regression

1. The wages for middle managers in a certain industry are thought to be no more than $45,000.00. A wage survey of 30 managers has a mean income of $46,260.00. Test the hypothesis at a 1% significance level. Does it appear that the average annual income is greater than $45,000.00? The population standard deviation is assumed

A question about null hypothesis is included.

In a study in which null hypothesis has been rejected, we should be aware of the possibility of ________ alternative hypotheses, Type II Errors, change due to new observations, all are correct This question is posed.

Multiple choice questions on testing of hypothesis

1.The power of a test is measured by its capability of a. rejecting a null hypothesis that is true. b. not rejecting a null hypothesis that is true. c. rejecting a null hypothesis that is false. d. not rejecting a null hypothesis that is false. 2. If an economist wishes to determine whethe

Statistical Analysis - Background Music

A researcher had the idea that background music might enhance performance on a math test and that the effect of music might depend on whether an individual is a music lover or not. She selected 50 music lovers and 50 control participants who did not listen to music on a regular basis. Half of the participants from each group t

Statistics: Multinomial, Neg Binomials and Hypothesis Testing

I have several questions I'm stuck on: 1. A production line produces good articles with probability .7, average ones with probability of .2, and defective ones with probability .1. Ten articles are selected. a) What is the probability of 8 good ones and 1 defective? b) What is the probability that there

Statistic Problems and Harassment

Employers sometimes seem to prefer executives who appear physically fit...Here are the data...c) You should also hesitate to conclude that increasing fitness causes an increase in ego strength. Explain why?

Null Hypothesis

2)Your company has recently changed suppliers of a certain raw material in an effort to reduce the number of defective units being produced at your plant. During the past year, the sampling has indicated a daily mean of 21.2 defective units. After testing the new suppliers raw materials for 30 days, it was found that the mean

Null Hypothesis

1)According to company figures, the age of a first time customer is normally distributed with an average age of 29.8 years and a standard deviation of 4.5 years. The marketing department has designed a new advertising strategy and wants to determine if this has had any impact on the average viewing age. Since the new ad campai

Computing the P-Value: The Iowa Department of Highways

An official of the Iowa Department of Highways wants to compare the useful life, in months, of two brands of paint used for striping roads. The mean number of months Cooper Paint lasted was 36.2 with a standard deviation of 1.114 months. The official review 35 road stripes. For King Paint, the mean number of months was 37.0 w

Hypothesis Testing and Power Functions

5.5.8 Let us say the life of a tire in miles, say X, is normally distributed with mean 0 and standard deviation 5000. Past experience indicates that 0=30,000. The manufacturer claims that the tires made by a new process have mean 0 >30,000. It is possible that 0=35,000. check his claim by testing H0: 0=30,000 against H1: 0 >

Statistics

1. Given the following N's (where N is the number of pairs of observations) and obtained r's, indicate whether the result is significant at the .05 level: (a) N = 100, r = .22 (b) N = 100, r = .60 (c) N = 9, r = -.70 (d) N = 36, r = .23 (e) N = 100, r = -.19 2. Given the following data, what are the correlation and the

Hypothesis Testing: Power functions

We say a critical region C is of size  if = max P{(X1,....,Xn)  C], 0 We define the power function of a critical region to be c()= P[(X1,...Xn) C], 1 1)Let X have a pdf of the from f(x; )= x^(&#615

Survey Responses

Using the large database of survey responses (this is your sample), you will begin testing hypotheses. Complete the following: 5. We will call a "desk body" a person whose intrinsic job satisfaction level is higher than their extrinsic job satisfaction level. We will call a "social body" a person whose extrinsic job sati

Statistics

In a 1999 survey, 55 of 100 randomly selected companies reported Internet sales. In a 2000 survey, 63 of 100 randomly selected companies reported Internet sales. For the alternative hypothesis HA: π1 ≠ π2 at level of significance 0.10, what is the value for the unknown population proportion, the critical values,

Statistics

Suppose the state department of real estate conducts a study of the number of first-time applicants who are successful in passing the state certification examination for real estate salespeople on their first attempt... What is the sample proportion of real estate employees who passed the exam on their first attempt? a. 0.26

Null hypothesis testing

3b) In this diagnostic, I will set the test a restricted model eliminating the 'smoking', setting this parameter to zero to test against the full regression model. (?) 3c)In this diagnostic, I will set the test a restricted model eliminating the as.factor(race)*ht, setting this parameter to zero to test against the full regre

Database analysis

I need to know which statistical test to use. I want to compare type of malaria contracted (4 categories) vs gender (M or F)so see if there is a) If there are more males than females catching ech of the four different malaria types and b)if there is a higher number of males and a higher number of females catching a particla

Hypothesis that women smile more

Louise was conducting a study to test her hypothesis that women smile more often than her male participants. Her hypothesis will probably be confirmed due to a. Social desirability b. Reactivity c. Experimentor expectancies d. Habituation I think that the answer is c. Am I on the right track?

Find the critical value of the test and apply decision rule

As a part of a class project, your statistics instructor asks you to weigh a sample of 100 items from a shipment of 500. You are testing the null hypothesis that the mean is greater or equal to 10 lbs. You are given that the standard diviation is 0.05 lb. Accepting H0 is the same as accepting the shipment. A) using a signific

Studying effects on small rewards on intrinsic motivation is listed.

Patrick was studying effects of small rewards (such as candy, gum, and soda pop) on intrinsic motivation. He tested fifth-grade children in a special room set aside by the school. Although he asked participants not to tell the students about the study, several children talked to their friends on the playground. Now some of hi

Significance Level

10.42 Nitrogen and Seagrass. The seagrass Thalassia testudinum is an integral part of the Texas coastal ecosystem. Essential to the growth of T. testudinum is ammonium. Researchers Kun-Seop Lee and Kenneth H. Dunton of the Marine Science Institute of the University of Texas at Austin noticed that the seagrass beds in Corpus C