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Hypothesis Testing

Samples, Populations, Normal Distributions

1. Based on a large number of recorded birth weights, the mean birth weight of babies born in the general population of the US is established at approximately 115 ounces. A sample of 50 birth weights was drawn randomly from the population consisting of all babies born to mothers who consumed two or more drinks per day during the

Methods for Predicting Crime Rates

I'm not sure where to start. Please see attached file for full problem description. John Wood works as a ranger for the Texas state police force. Lately, he has noticed an alarming trend toward higher recidivism rates by criminals in several southwestern counties in Texas. Law enforcement agencies are concerned about the e

Quick Stab Collection Agency (QSCA), is a bill-collecting agency.

Please see attached file for full problem description and the data to do the hypothesis. Please show all work and write the analysis. Thanks Quick Stab Collection Agency (QSCA), is a bill-collecting agency. The company specializes in collecting small accounts. The marketing department has just suggested that QSCA adopt

Comparison of Annual Dividends

A random sample of 85 utility stocks was taken to compare the amount of their annual dividends to the annualized yields of the dividends. The data are given in following Table (see attachment) a. Find the correlation coefficient. b. Can we conclude that the variables are positively associated within the population of a

Find the test statistic, p-value and critical value and state a final conclusion

Find the test statistic, p-value and critical value and state a final conclusion. Caim: The mean IQ score of statistics professors is less than 120 sample data: n=40, mean of the values in a sample = 117, assume that the standard deviation = 14 and the significance level = 0.05 Calculate the test statistic ( round to ne

P-Value Method on Purchasing Textbooks

Suppose a study is conducted to test the claim, at a 0.01 significance level, that less than 75% of college students spend less than $250 per semester on text books. A survey of 700 students found that 71% spent less than $250 per semester on texts List the claim using the P-value method Determine the p-value (round to fo

Hypothesis Testing of Waiting Times at Fast-Food Chains

The waiting time to place an order at a branch of a fast-food chain during the lunch hour has had population mean of 3.55 minutes, with a population standard deviation of 1.1 minute. Recently, in an effort to reduce the waiting time, the branch has experimented with a system in which there is a single waiting line. A sample of

Graphical Devices for Checking Test Results

1. A random sample of 10 college students was drawn from a large University. Their ages are 22, 17, 27, 20, 23, 19, 24, 18, 19, and 24 years. What is the required condition to test to determine if we can infer that the population mean is not equal. What graphical device can you use to check to see if that required condition

Population Mean of Waiting Time Analysis

You are the manager of a restaurant for a fast food franchise. Last month, the mean waiting time at the drive-through window, as measured from the time a customer places an order until the time the customer receives the order, was 3.7 minutes. The franchise helped you institute a new process intended to reduce waiting time. Yo

Violation of Speed Limit Analysis

Do out-of-state motorist violate the speed limit more frequently than in-state motorists? This vital question was addressed by the highway patrol in a large eastern state. A random sample of the speeds of 2,500 randomly selected cars was categorized according to whether the car was registered in the state or in some other stat

Statistic Tests on Publisher and Manager Questions

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

Vehicle Emissions Test

State DMV records indicate that of all vehicles undergoing emissions testing during the previous year, 70% passed on the first try. A random sample of 200 cars tested in a particular country during the current year yields 156 that passed on the initial test. Does this suggest that the true proportion for this country during the

True or False, Multiple Choice Questions

1. For a specific confidence interval, the larger the sample size, the smaller the maximum error of estimate will be. T 2. An estimator is consistent if, as the sample size decreases, the value of the estimator approaches the value of the parameter estimated. ____ T/F 3. When we reject the null hypothesis, we are c

Critical T-Value

Find the critical t-value that corresponds to c = 0.95 and n = 16.

Type I and Type II Errors

Type I and Type II Errors In this scenario, (1) formulate both a null and (2) research hypothesis and give an example of both a (3) Type I and (4) Type II error. Scenario: You are Supervisor or Research for Doggie Heaven Biscuit Company. Your scientists have developed a new dog biscuit for the treatment of doggie breath. I

Frequency Hypothesis Test

Please see attached file for full problem description. Please help with the areas in red, thanks! Frequency Hypothesis Test #4) Does it seem to you that people tend to be absent more on some days of the week than on others? Recently, a major biotechnology firm collected data with the hope of determining whether or not it

Test of Hypothesis for the Average Gasoline Price

The average gasoline price of one of the major oil companies has been $2,25 per gallon. Recently, the company has undertaken several efficiency measures in order to reduce prices. Management is interested in determing whether their efficiency measures have actually reduced prices. That is, the alternative hypothesis is that

One tailed test of Hypothesis

The McCollough Corporation, a producer of various kinds of batteries, has been producing D size batteries with a life expectancy of 87 hours. Due to an improved production process, the management believes that there has been an increase in the life expectancy of their D size batteries. A sample of 36 batteries showed an averag

Investigate the effects of prenatal alcohol on birth weight.

1. A researcher wants to investigate the effects of prenatal alcohol on birth weight. A random sample of n = 16 pregnant rats is obtained. The mother rats are given daily doses of alcohol. At birth, one pup is selected from each litter to produce a sample of n = 16 newborn rats. The average weight for the sample is 15 grams. The

Differences in the abilities of five treatments to stimulate growth

The data in the attachment below represents the weight (mass) gained by 50 corn plants over a 3 week period. 10 plants each were given growth stimulators (labeled A, B, C, and D) and 10 plants were given no stimulator(that treatment is labeled S). Use the one-way anova capabilities of Excel to determine whether there ar

Comparison of Samples

(a) state the decision rule, (b) compute the pooled estimate of the population variance, (c) compute the test statistic, (d) state your decision about the null hypothesis, and (e) estimate the p-value. The null and alternate hypotheses are: Ho: µ1 = µ2 Ha: µ1 ≠ µ2 Please use the five-step hyp

Sample selected from normally distributed population

Assume that a sample random sample has been selected from a normally distributed population. Find the test statistic, a range of numbers for the p-value, critical value, and state the final conclusion. Claim: The mean bottom temperature of a fish breeding pond is less than 20.0 Celcius Sample Data: n=61 X(with a line on top)

Differences between out of pocket costs between in-network

THE PROBLEM: This week we would like to perform a two-tailed test and use the .05 significance level, estimate the p-value, and interpret it to determine differences between out of pocket costs between in-network and out-of-network dental plans. The following chart is dental members and the values are dollars out of pocket e