Explore BrainMass

Explore BrainMass

    Hypothesis Testing

    BrainMass Solutions Available for Instant Download

    Null Hypothesis Modifications

    Problem: Ford Taurus travels 21 mi. while consuming exactly 1 gallon of gas. You developed a modification to the engine you believe increases the distance. If you want to justify your claim of increased mileage by using a hypothesis test, is it possible to state your claim so that it becomes the null hypothesis? Why, why not?

    Help 4

    Metro Real Estate Association is preparing a pamphlet that they feel might be of interest to prospective homebuyers in the Middletown and Brockton areas of the city. One item of interest is the number of years that children remain in the same district for schooling. A sample of 40 households with school-aged children in Middleto

    hypothesis test for difference in means using a z-statistic

    A study was conducted on the annual incomes of corporate trainers in the state of New York, in metropolitan areas of less than 100,000, and in metropolitan areas having a population of over 500,000. Some sample statistics are: Sample Statistic Population less than 100K Population more than 500K Sample Size 45 60 Sample Mean

    Hypothesis test

    A sample of 40 observations is selected from one somewhat normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean was 99 and the standard deviation was 6. Conduct a test of the hypothesis using the .04 level of significance.

    The new director of special programs in XYZ Corporation...

    The new director of special programs in XYZ Corporation felt the customers were waiting too long to receive and complete forms needed to enroll in special programs. After collecting some data, Ms. Jones determined the mean wait time was 28 minutes. She felt this time period was in excess, and she instituted new procedures to str

    Test of Hypothesis and about P-Value

    Health care reform was one of the major platforms of the Clinton campaign in 1992 and one of the top priorities of his new administration in 1993. One of the polls taken after President Clinton's inauguration indicated that 273 of 521 registered voters believed that health care reform should be the leading priority of the new p

    Inference

    An insurance company is thinking about offering discounts on its life insurance policies to nonsmokers. As part of its analysis it randomly selects 200 men who are 60 years old and asks them whether or not they smoke at least one pack of cigarettes per day and whether they have ever suffered from heart disease. The results are s

    Inference in the Yellow Pages Effect

    To determine the effect of advertising in the Yellow Pages, Bell Telephone took a sample of 40 retail stores that did not advertise in the Yellow Pages last year but did so this year. The annual sales(in thousands of dollars) for each store in both years were recorded and stored in file yellow pages a. Estimate with 90% confide

    Inference

    One factor in low productivity is the amount of time wasted by workers. Wasted time includes time spent cleaning up mistakes, waiting for more material and equipment, and performing any other activity not related to production. In a project designed to examine the problem, an operations management consultant took a survey of 200

    Hypothesis test to determine is patient care exceeds 45 hours

    The American Medical Association conducts surveys of its members each year. A sample of physicians is selected and asked to report the amount of time each devotes to patient care each week. The results for the survey are stored in the excel file. Can we infer that the mean amount of time devoted to patient care per week by all p

    restaurant site is acceptable based on pedestrian traffic.

    A fast food franchiser is considering building a restaurant at a certain location. Based on financial analyses, a site is acceptable only if the number of pedestrian passing the location averages more than 100 per hour. The number of pedestrians observed for each of 40 hours was recorded and stored in the attached excel file .

    Z-estimate

    In an attempt to reduce the number of person-hours lost as a result of industrial accidents, a large production plant installed new safety equipment. In a test of the effectiveness of the equipment, a random sample of 50 departments was chosen. The number of person-hours lost in the month prior to and the month after the install

    Expectation and Hypothesis Testing

    4. An experiment is set to test the hypothesis that a given coin is unbiased. The decision rule is the following: Accept the hypothesis if the number of heads in a sample of 200 tosses is between 90 and 110 inclusive, otherwise reject the hypothesis. a) Find the probability of accepting the hypothesis when it is correct.

    Statistics problems

    Please explain fully, using Excel when necessary. These questions were addressed once already, but they were not explained in a way in which they could be fully understood. Please detail each step. 1) A publisher is considering three different covers for a new magazine. A random sample of 90 people are asked to pick their fa

    General Statistics P-Value and Significance Levels

    Please use Excel when necessary: 1) When the p-value is smaller than the significance level: a) A type 1 error is committed b) A type 11 error is committed c) The null hypothesis is rejected d) The critical value is correct. Problem # 2) The coefficient of correlation between the variables X and Y was computed to be -0.6

    No Differences Between the Two Groups of Subjects

    A) Analyse the data below to test the hypotheses that there are no differences between the two groups of subjects in terms of their walking time to exhaustion (in seconds) and ratings of perceived exertion (RPE) after 8 minutes of walking. Healthy subjects --------------------------------------------------------------------

    Sample proportion hypotheses test

    Ho: P<= .7 Ha: P > .7 Sample Data Set: 300 Sample Proportion of .853 What is the standard error of the proportion? What is the z-test? How do you compute the p value? What do you do with the Ho?

    Biopstatistics Problem

    I hope you can help me with this problem. I have 2 questions regarding this study. 1) I have heard from my teacher that there is a 7th null hypothesis hidden in the text for this study. The first 6 are presented in the tables. WHAT IS THE 7TH NULL HYPOTHESIS??? They are: Ho1: Cr 3+and As3+ has no effect on glucose to

    Using Spearman's - Is my data statistically significant?

    Hi there, I used excel to analyze my data with spearmans rank order co efficient test and came up with the attached table. I have a query about finding out whether my correlation coefficient - 0.420- is statistically significant. This is what i understand (not much!) - take the t value and compare it to the critical val

    Statistics Differences using Absolute Values in ANOVA

    Optional Extra Credit Project Due June 14 Good for up to 10 points, depending on how thorough and creative your work is. Please make sure to show me everything in order to receive the greatest benefit. Please evaluate the following null hypothesis, and apply the principles of statistical inference as appropriate. T

    Population mean

    What is your estimate of the range of differences between population means? How much confidence (expressed as a percentage) do you have in that estimate?

    What you need to know about null hypothesis?

    Here is the scenario: Suppose we hypothesize that there is a negative (inverse) relationship between treatment and depression. We'd like to test this hypothesis, so we obtain two samples. Sample 1 is drawn from a population of depressed persons who have not received any type of treatment. Sample 2 is drawn from a population o