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Hypothesis Testing

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 >


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


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,


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

Test of independence

This is a generic question: A researcher who uses a "test of independence" to analyze his data in using a(n) a. Two way chi-squared test b. Independent-samples-test c. Dependent-samples t-test d. Meta-analysis

Ten true-false questions about the sample mean and sample variance calculated on a sample from a normal distribution and using the mean and standard deviaton when testing hypotheses.

Please use words to describe the solution process. In the statements that follow, X is a normally distributed random variable with mean [symbol1] and variance [symbol2]. Furthermore, X1,...,Xn are independent random variables wit the same distribution as X ... Please see attachment for complete question and proper citation

Independent & Dependent variables

Choose a hypothesis and operationally define a variable in the hypothesis. Your operational definition will consist of measures at the self-report, behavioral, and physiological levels as well as a manipulation of the variable. Your operational definition should be written in such a way that you could measure and manipulate it


10.48 Nitrogen and Seagrass. Refer to Exercise 10.42. a. Determine a 98% confidence interval for the difference, M1-M2, between the mean sediment ammonium concentrations in CCB and LLM.

Inferences from Two Samples

A) State the null and alternate hypothesis. B) Determine the rejection region. For example "if , then reject ". C) Determine the Test Statistic. D) Conclude either "Reject " or "Do not reject " based on your analysis and answer the question. E) Determine the p value of the test. Note: Please show how everything was

Sample z test

Directions: Perform a one sample z test for a population mean using the p value approach. Be sure to state the hypothese and the significance leve, to compute the value of the test statistics, to obtain the p value and to state your conclusion. Question: In 1990, the average duration of long distance telephone calls originati

Test of hypothesis, Sample Size

1. Erthromyacine is a drug that has been related with side effects during pregnancy. Assume that 30% of women experience side effects between the 24th and 28th week of pregnancy. Furthermore suppose that of 200 women who are taking the drug 110 complain of nausea. Test the hypothesis that the incidence rate of nausea for the dr

Sample / Standard Deviation

In a study of quantities of rice consumed in two different cities, a sample data looks as in the attachment. Sampling units were families of four, data is for a year. a. Would it be reasonable to conclude (95 percent confidence) that the two cities were statistically different in the average quantities of rice they consumed p