Explore BrainMass

# Hypothesis Testing

### Statistics - Null and Alternative Hypothesis, Type 1 Error

Some college graduates employed full-time work more than 40 hours per week, and some work fewer than 40 hours per week. We suspect that the mean number of hours worked per week by college graduates mean (mu) of a population, is different from 40 hours and wish to do a statistical test. We select a random sample of college gradua

### Null and Alternative Hypothesis for a Decade Old Study

A decade-old study found that the proportion of high school seniors who felt that "getting rich" was an important personal goal was 67%. Suppose that we have reason to believe that this proportion has changed, and we wish to carry out a hypothesis test to see if our belief can be supported. State the null hypothesis H0 and the a

### Null and alternative hypothesis

A manager of an electronics store wants to know if the average sales during the Christmas period is greater than \$ 30,000 a week. The null hypothesis to be formulated to test hypothesis is: The correct answer is a) HI = 30.000 or b) Ho = 30.000 or c) Ho <30.000 or d) Ho = 40.000 The correct answer for the altern

### How does the Sun produce energy?

A bank tests the null hypothesis that the mean age of the bank's mortgage holders is less than or equal to 45, versus an alternative that the mean age is greater than 45. They take a sample and calculate a p-value of 0.1202. What can the bank conclude about the alternative hypothesis? Your answer must be given in the form of a

### Starbucks Problem 16.17 Applied Statistics

Thirty four customers at Starbucks either ordered coffee (C) or did not order coffee (X) Research question At a=0.5, what is the sequence random? Here is the sample cxcxccccxxxxcxcxcxcccxcxccxcxxxccx

### Statistics - Hypothesis Testing and Profit Distribution

1. A manufacturing firm recruits 45 new sales staff, and sends each on one of two training courses. 25 attend course A, and 20 attend course B. The sales figures are then collected for the following six months and the following summary statistics are produced from profits X (in pounds) generated from these sales: (see attach

### Data Sets: T-tests vs. Z-tests

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, determining the appropriate critical value, selecting the test statistic and determining its value from the sample d

### Statistics - Hypothesis tests...

Hypothesis tests for the correlation coefficient and the slope of the least-squares regression line The Cadet is a popular model of sport utility vehicle, known for its relatively high resale value. For a random sample of Cadets, each bought "new" two years ago and each sold "used" within the past month, the sample correlatio

### Statistics of Plant Heights

Heights were measured for a random sample of 20 plants grown while being treated with a particular nutrient. The sample mean and sample standard deviation of those height measurements were 39 centimeters and 12 centimeters, respectively. Assume that the population of heights of treated plants is normally distributed with mea

### Statistics - Hypothesis Testing (Z-Testing).

4. The average monthly cot for a studio apartment in NYC is reported to be \$1,000. You want to prove that average monthly rent is not what is stated. You collect a random sample of 25 rents in all areas and find that the sample mean is \$961 and the sample standard deviation is \$110. Can you disprove the claim at the &#61537;

### Hypothesis Testing (Z-Testing)

A doctor suspected that smokers between 40 and 50 with lung disease had been smoking on average more than 20 years. A sample of 10 smokers gave the following results: 22 2 19 25 24 26 23 2 21 22 Using a 1% significance level is there sufficient evidence to justify the doctors belief? Is there sufficient evidence t

### Statistics: Testing the Null Hypothesis

Please show all calculations on every problem. 1. A machine produces 3-inch nails. A sample of 12 nails was selected and the lengths determined. The results are as follows: 2.89 2.95 3.00 3.05 2.99 2.96 3.10 3.06 3.00 3.12 3.00 2.95 Use these results to test H0: u = 3 and Ha: u does not = 3 at alpha = 0.05. Give the crit

### Conducting a One-Tail Hypothesis Test

Given the following data from two independent data sets, conduct a one-tail hypothesis test to determine if the means are statistically equal using alpha=0.05. Do not do a confidence interval. n1 = XX n2 = XX xbar1= XXXX xbar2 = XXXX s1=XXX s2 = XXX

### Samples, Testing, and Variables

1. Classify the following as independent or dependent samples: a. The effectiveness of two blood pressure medicines on two groups of patients. b. Measures of gas mileage and speed for a group of race cars. c. Scores of a group of nurses on the NCLEX nursing license exam. 2. Please answer the following. a. Explain the d

### Statistics - Null and Alternate Hypothesis.

1. The null hypothesis Ho: 2. The alternate hypothesis H1: 3. The type of test statistic __ (F, Z, chi square t) degrees of freedom __ 4. The value of the test statistic: round to at least three decimal places 5. the p-value (round to at least three decimal places) 6. Based on the data, can the professor conclude (using th

### Hypothesis testing problems

1. Classify the following as independent or dependent samples: a. The effectiveness of two blood pressure medicines on two groups of patients. b. Measures of gas mileage and speed for a group of race cars. c. Scores of a group of nurses on the NCLEX nursing license exam. 2. Please answer the following. a. Explai

### Estimation and Test of Hypothesis

1. When the means of two unrelated samples are used to compare two populations, we are dealing with two dependent means ___ T/F 2. If standard deviation is unknown when completing a hypothesis test about the population mean, then the best estimate for the unknown standard deviation is s. _____ T/F 3. The number of d

### P-value for Fast Food Companies

1. Determine the p-value for H0: p=.5 versus HA: p =/ (difference) .5 when n=225 and p^ =.54. 2. A fast food company uses two management-training methods. Method 1 is a traditional method of training and Method 2 is a new and innovative method. The company has just hired 36 new management trainees. 15 of the trainees are

### Significance Level for Accompanying Data

The accompanying data are the times in seconds that it took a sample of employees to assemble a component at Ental Industries manufacturing facility. Assembly times are normally distributed. At the .05 significance level, can we conclude that the mean assembly time for this component is not equal to 3 minutes? Use HA: &#61549;

### Statistics - Hypothesis..

1. is the data normally distributed? (use the formula for pearson index) 2.the average cholesterol should be less than or equal to 200. Does the above data support this hypothesis if a =.10? 1. Find Q1, Q2, Q3 (quartiles) 2.is the data normally distributed (use the formula for pearson index) 3.come up with a hypot

### Two-Tail Hypothesis Testing and Confidence Intervals

1. A certain type of cable was advertised as having a breaking strength of 1000 pounds. A test of XX pieces of this cable was conducted and the mean breaking strength of this sample was XXX pounds with a sample standard deviation of XX pounds. Conduct a two-tail hypotheses test at alpha = .05 to determine if this sample data pro

### Significance Levels, P-Values, and Confidence Intervals

You are investigating the flight characteristics of different kinds of birds. You collect a sample of 33 European swallows (Hirundo rustica) and measure their air-speed velocity in a borrowed wind tunnel. You find the mean air-speed velocity to be 11 meters/second with a standard deviation of 3 meters/second. You then collect a

### Hypothesis testing problems from 'Applied Statistics in Business and Economics by David P Doane and Lori E. Seward, McGraw Hill; 1st Edition (2006) '

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 &#945; = .01, did the yellow fire trucks have a significa

### Mean

A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of \$5.29 with a standard deviation of \$3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was \$5.12 with a standard deviation of \$2.14. The means appear to be very close,

### Hypotheses

Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study, researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age 58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the inactive pill. (a) State the

### Statistical Tests, Hypothesis Testing, p-Values, and Sample Size

1. Classify the following as independent or dependent samples: a. The effectiveness of two blood pressure medicines on two groups of patients. b. Measures of gas mileage and speed for a group of racecars. c. Scores of a group of nurses on the NCLEX nursing license exam. 2. Please answer the following. a. Expla

### Salary equity study of faculty at a certain university

#1 in a salary equity study of faculty at a certain university, the salaries of 50 male assistant professors showed a sample mean of \$36,400 with a sample standard deviation of 360, whereas the salaries of 50 female assistant professors chosen independently showed a sample mean of \$34,200 with a sample standard deviation of 220.

### Hypothesis Testing Problems and Confidence Intervals

1. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 175 was taken, and the mean amount spent was \$250. Assuming a standard deviation equal to \$45, find the 95% confidence interval for mu, the mean for all such families. 2. What sample size would b

### Null Hypothesis of M&M colors with ANOVA

The weights (in grams) of four different colors of M&M candies are given below, along with the mean weight and variance of each color, and the variance of the sample means. Use a one-way ANOVA at the 0.025 significance level to test the null hypothesis that the different color M&M candies have the same mean weight. Red Oran

### Numerical Hypothesis Statement for Wages

Is the annual average wage of unmarried people (18 - 30) the same as that of married people (31 - 43)? Hypothesis Statements: H0: The mean annual wages of unmarried people (18 - 30) is the same as that of married people (31 - 43) Ha: The mean annual wages of unmarried people (18 - 30) is different from that of marrie