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Hypothesis Testing

Two-Tailed Test and P-Value

The top food snacks consumed by adults aged 18-54 are gum, chocolate candy, fresh fruit, potato chips, breath mints/candy, Ice cream, nuts, cookies, bars, yogurt, and crackers. Out of a random sample of 25 men, 15 ranked fresh fruit in their top five snack choices. Out of a random sample of 32 women, 22 ranked fresh fruit in the

Population of Interest

Populations of Interest Many believe that GM's demise could lead to a ripple effect and cause many other businesses to go under. This ripple effect, many think, could cause the United States to slip out of a recession and lead the country into a depression. The group will research this effect to see what populations could be


A sample of size 25 provides a sample variance of 400. The standard error, in this case equal to 4, is best described as the estimate of the standard deviation of means calculated from samples of size 25. Blossom's Flowers purchases roses for sale for Valentine's Day. The roses are purchased for $10 a dozen and are sold for

Degrees of Freedom

A political scientist obtained recordings of election-night acceptance speeches of seven newly elected representatives to the US Congress. She counted the number of minutes devoted to urban problems in these speeches. Four of the representatives were from rural districts and three were from urban districts. Listed below are the

How do you integrate ethics in your professional decision making process?

What is ethics? Ethics is basically concerned with the Moral obligations, responsibilities and social justice of the world. It invokes the idea of "how people should act". What is morals? Morals is your ability to know the difference between good and bad. Ethics is a construct made up of values. Ethical values include love, hone

CHAPTER 10: Normality Assumption (10.30) In Dallas, some fire trucks were painted yellow (instead of red) to heighten ... (11.24) In a bumper test, three types of autos were deliberately crashed ... (10.44) Does lovastatin reduce the risk of heart attacks? In a Texas study ... (10.46) To test the hypothesis that students who finished an exam first get ... 10.56) A sample of 25 concession stand purchases at the October 22 matinee Bride of ...

(10.30) In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At α = .01, did the yellow fire trucks have a signific

Statistics Random Samples Z-Test

For the following independent random samples, use the z-test and the 0.01 level of significance in testing Ho:u1 = u2 versus H1:u1 = u2. x1 = 33.5 s1 = 6.4 n1 = 31 x2 = 27.6 s2 = 2.7 n2 = 30 2. The manager's assistant, who created a new brochure, randomly selects 400 current customers, then randoml

Calculate mean and standard deviation from a sample a perform a hypothesis test.

7. Employer A states the average number of days missed in a year by each staff member is 4.0. Office personnel randomly sampled a portion of their attendance records to determine if this claim was accurate. For the previous year, the following data was obtained from the sample group, regarding absences for that year: 4, 4, 3,

Statistics: P-value, Standard Deviation

Please show work! 1. A bottling company needs to produce bottles that will hold 8 ounces of liquid for a local brewery. Periodically, the company gets complaints that their bottles are not holding enough liquid. To test this claim, the bottling company randomly samples 64 bottles and finds the average amount of liquid held by t

5 Step Hypothesis Test - 2 Sample

10.30. In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At α = .01, did the yellow fire trucks have a significa

statistics: Calculating P-value

Give the p-value for the hypothesis test. For testing the null hypothesis at the 4% level of significance that mu GE 100 vs the alternative that mu < 100, the test statistic is:

Hypothesis Testing: Types of Samples

PROBLEM: Target wants to maintain adequate supplies of various brands of mouthwash to meet the on-going demands of its customers. Target wants to estimate the proportion of its customers who favor the country's leading brand of mouthwash, Scope. Are the data convincing evidence that something other than the historical 13% pre

Perform and independent samples t testt

You are interested in a new method of advertising. In order to test the new procedure they have tested it in eleven markets with the following sales in thousands of dollars: $124; $157; $98; $190; $103; $135; $149; $176; $200; $180; and $256. You also used eleven control markets, which had the following sales in thousands of d

Hypothesis test.

Research has demonstrated that involvement in religious activities seems to benefit health and well-being. Reyes-Ortiz, Ayele, Mulligan, Espino, Berges, and Markides (2006) found that church attendance was significantly related to fear of falling in a sample of Mexican-American aged 70 and over. The following frequency distri

Hypothesis Testing: Confidence Intervals

7. In a packing plant a machine packs cartons with jars. Supposedly a new machine will pack faster on the average than the machine currently used. To test that hypothesis the time it takes each machine to pack 10 cartons are recorded. The results in seconds are shown in the following table. New: 42,41,41.3,41.8,42.4,42.8,43.2,

Z test for population proportion

5. Of the 38 numbers on a roulette wheel, 18 are red, 18 are black and 2 are green. If the wheel is balanced, the probability of the wheel landing on red is 0.474. A gambler has been studying a roulette wheel. If the wheel is out of balance then he can improve his odds of winning. The gambler observed 200 spins of the wheel and

Statistics - Conclusion based on given data

The US energy administration publishes data on residential energy consumption and expenditures in residential consumption survey: consumption and expenditures. Suppose you want to decide whether last years mean annual mean expenditure for house holds using natural gas is different from that for house holds using only electricity

Standard Deviation

College work study students earned a mean of $1252. Assume that a sample consisiting of 45 of the work study students at a large university was found to have earned a mean of $1277 during that year, with a standard deviation of $210. Would a one-tail test at the 0.05 level suggest the average earnings of this university's wor

One Tail/Two Tail Rejection Regions

1. For each of the following statements, formulate appropriate null and alternative hypothese, indicate whether the appropriate test will be one-tail or two-tail, then sketch a diagram that shows the approximate location of the rejection region(s) for the test. a. The average college student spends no more than $300 per seme

Population Mean

A consumer agency has retained an independet testing firm to examine a television manufacturer's claim that its 25-inch console lmodel consumes just 110 watts of electricity. Based on a preliminary study, the population standard deviation has been estimated as 11.2 watts for these sets. In undertaking a larger study, and using

Statistics: Level of Significant Problems

The average length of a flight by regional airlines in the United States has been reported as 299 miles. If a simple random sample of 30 flights by regional airlines were to have x = 314.6 miles and s = 42.8 miles, would this tend to cast doubt on the reported average of 299 miles? Use a two-tail test and the 0.05 level of sig

Independent Variables and Statistics Tests

EXHIBIT 1: A manager at a local bank analyzed the relationship between monthly salary and three independent variables: length of service (measured in months), gender (0=female, 1=male) and job type (0=clerical, 1=technical). The following tables summarize the regression results: df

Effects of TV viewing on reading scores

Dr. S wishes to measure the effect of TV viewing on reading scores in elementary school children. The data for the sample are shown here. Assume the population is normal. # hours TV/week (x): 4,5,8,12,20,16,20,22,22,25,30 Reading scores (y):805,810, 860,750,715,755,720,635,615,540,500 a.Construct a scatter plot using Mini

Applying statistics for smokers and nonsmokers

Dr. Z at the Clinic wishes to see whether the pulse rates of smokers are higher than the pulse rates of nonsmokers. Samples of 100 smokers and 100 nonsmokers are selected. The results are shown here. Can Dr. Z conclude, at alpha = 0.05, that the smokers have higher pulse rates than nonsmokers? Assume the samples come from a no

Creating Statistical analysis in SPSS and Interpreting Results

Introduction and Methods section: Impulse-Control disorder is a formal DSM IV disorder and is a core symptom that is found across an array of psycho-pathological conditions and consequently contributes to a large number of mental health problems in society. As cited in the Diagnostic and Statistical Manual of Mental Disorders

Planning Habits Survey/Null and alternative hypothesis

American Demographics reported the results of a survey on the planning habits of men and women. In response to the question. "What is your preferred method of planning and keeping track of meetings, appointments, and deadlines?, 56% of the men and 46% of the women answered "keep them in my head". A nationally represented sample

Critical value to reject the null hypothesis

Dr. Easy saw the scores from the MA-222 test and used the occasion to test the old adage that girls are smarter than boys on subjects tested by ACT. Assume the degrees of freedom for this problem is 28. Dr. Easy did the arithmetic and found the value of the test statistic was 2.69 (alpha equals .05). What is the critical value (

P-value Stat Question

In a test of hypothesis, the null hypothesis is that the population mean is equal to 60 and the alternative hypothesis is that the population mean is not equal to 60. A sample of 36 elements selected from this population produced a mean of 63 and a standard deviation of 6.3. What is the approximate p-value for this test?

Hypothesis testing: chi square and z-stat. At the .05 level of significance, test the claim that at least half of all voters prefer the democratic candidate. Test the claim that the proportion with the lawn mowers is higher than 65%. Use a .01 significance level to test the claim that for men without college degrees in that town, incomes have a higher standard deviation when a random sample of 22 men resulted in incomes with a standard deviation of 925$

1. A poll of 1,068 Americans reveals that 48% of the voters surveyed prefer the Democratic candidate for president. At the .05 level of significance, test the claim that at least half of all voters prefer the democratic candidate. 2. A nationwide study of American homeowners revealed that 65% have one or more lawn mowers. A l