Explore BrainMass

# Hypothesis Testing

### 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

### Test of hypothesis: At 95% confidence, test to determine whether or not the lathe is in perfect adjustment.

A lathe is set to cut steel bars into lengths of 6 centimeters. The lathe is considered to be in perfect adjustment if the average length of the bars it cuts is equal to 6 centimeters. A sample of 25 bars is selected randomly, and the lengths are measured. It is determined that the average length of the bars in the sample is

### Statistical Significance - You are a researcher who is interested in the effect of child care on the attachment which develops between an infant and a caregiver.

You are a researcher who is interested in the effect of child care on the attachment which develops between an infant and a caregiver. You believe that infants in child care will be insecurely attached at 11 months after being in child care from 2 months of age, compared with infants who are cared for at home by their mother

### 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

### Statistics Question: Light Bulb Manufacturer

Trying to set up the analysis of a manufacturer of fluorescent light bulbs states that on the average, these light bulbs have a lifetime of 1600 hours. A sample of 100 bulbs was tested and the mean lifetime was 1570 hours with a standard deviation of 120 hours. Do these bulbs have a lifetime of 1600 hours? Test at .05 and .01

### Perform a t-test by formulating a null and an alternative statement

Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test s

### 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 &#8800; µ2 Please use the five-step hyp

### Suppose that the scores of architects on a particular creativity test are normally distributed

Suppose that the scores of architects on a particular creativity test are normally distributed. What percentage of architects have z scores (a) above .10 (b) below .10 (c)above .20 (d) below .20 (e) above 1.10 (f) below 1.10 (g) above -.10 (h) below -.10

### 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)

### Hypothesis testing :Proportion

In a study of check out scanners, 5 of 675 items were found to be overcharges, test at the 0.05 significance level, the claim that with scanners, 5% of sales are overcharges. Determine the test statistic. Do not round until the final step. (round to nearest hundredth)

### Determining the Statistic

Suppose a study is conducted to test the claim, at a 0.05 significance level that a population proportion is 30%. A simple random sample 680 subjects has a proportion of 35%. Determine the test statistic. (round to nearest hundredths as needed).

### 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

### Standard Normal Random Variable

Let Z be a standard normal random variable. Determine the value of c such that P (Z > c) = 0.1251 is there a way to do this step by step so i can understand it?

### Hypothesis Testing of Treatment Means

Given the following sample information, test the hypothesis that the treatment means are equal at the .05 significance level. Treatment 1 Treatment 2 Treatment 3 3 9 6 2 6 3 5 5 5 1 6 5 3 8 5 1 5 4 4 1 7 5 6 4 a. State the null hypothesis and the alternate hypothesis. b. What is th

### Hypothesis Testing of Watching TV

I am having a difficult time trying to figure out this problem about a random sample of 480 male and female adults which were asked the amount of time each person spent watching TV last week. Their responses are below. Gender of Viewer Hours Male Female Total Under 8 70 90 160 8 to 15

### Some hypothesis testing problems

Assume that a hypothesis test of the given claim will be conducted. The college Dean of Admissions claims that the times students require to earn a bachelors degree have a mean less than five years. Which equality/inequality (e.g., =, =<, etc.) would use in the Null Hypothesis? Assume that a hypothesis test of the giv

### statistical test to perform as well as the test actually perform

Need to know what statistical test to perform as well as the test actually performed. If a program is used need scanned copy of printout and if by hand, need explanation. Additionally, I would like a brief explanation about the test and why it was chosen. It is not a homework problem but something I need to test experimental

### Parametric and Nonparametric Data Identification

Jim owns three real estate offices in Anytown. He has decided to open one more office, but cannot decide between hometown or uptown as the towns where he wants to locate. He will be comparing the mean number of homes sold per real estate agent, and the mean commission percentage earned by agents in the two towns to make his dec

### Parametric vs. Nonparametric Data Identification

A manufacturer produces a batch of memory chips (RAM) and measures the mean-time-between failures (MTBF). the manufacturer then changes a manufacturing process and produces another batch and again measures the MTBF. did the change to the process improve the MTBF? How do I determine if this is parametric or nonparametric?

### Hypothesis Test for Means

1. The mean age of bus drivers in Chicago is 54.5 years. If a hypothesis test is performed, how should you interpret a decision that fail to rejects the null hypothesis? A There is sufficient evidence to reject the claim mean = 54.5 B There is not sufficient to reject the claim mean = 54.5 C There is sufficient evidence to

### Hypothesis Testing with Z-Test

Please show your work in Excel if possible. Hypothesis test for the difference of population means: Z test According to the historical data, the life expectancy in the United States is equal to the life expectancy in the United Kingdom. A new study has been made to see whether this has changed. Records of 200 individuals fro

### At the time she was hired as a server at the restaurant

Please include output so I can see the formulas. Please include Hypthoseses. Please complete the graph. File attached.

In a recent study, a researcher found that there is a negative correlation (r = -0.67) between changing your first answer on a standardized achievement test and test scores. Apparently, according to the study, students are changing the correct answers for incorrect ones. Based on this study, should you consider changing your ans

### Setting Up For Standard Deviation

The end of the year can be a time of rejoicing, a time of business, and a time of confusion. For most employers, it is a time to conduct open enrollment for its employees. For employers and employees, this can be a very confusing time with all of the options made available for the health care industry. The summary detailed be

### Decision Rule

Please show in Excel spreadsheets 1) The restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a stdev of 1 minute. The quailty assurance department found in a sample of 50 customers at another place that the mean waiting time was 2.75 minutes. At a .05

### A study was conducted to determine the effects of sleep deprivation on student's ability to solve problems.

Please see attached file for full problem description. A study was conducted to determine the effects of sleep deprivation on student's ability to solve problems. The amount of sleep deprivation varied over 8, 12, 16, 20, and 24 hours without sleep. A total of ten subjects participated in the study, two at each deprivation le

### A manager of the credit department for an oil company would like to determine whether the average monthly balance of credit card holders is equal to \$75.

Please provide a brief explanation if possible of how to arrive at these answers. Please see attached file for full problem description. 1. Suppose we wish to test H0: 47 versus H1: > 47. What will result if we conclude that the mean is greater than 47 when its true value is really 52? a) We have made a Type I error.

### Explanation of Probability Value and Significance Level

What is the difference between the probability value and the significance level? Please, also provide examples.