Based on the information given for each of the following studies, decide whether to reject the null hypothesis. For each, give the Z-score cutoff (or cutoffs) on the comparison distribution at which the null hypothesis should be rejected, the Z score on the comparison distribution for the sample score, and your conclusion. Assum
For items 1 to 4, select the best statistical analysis technique for the following research topics. Be very precise about your statistical choice. For example, there are several types of t-tests, correlations, and ANOVA tests. Make sure you specify exactly which statistical analysis technique you would use, e.g. One-Way Anova
List the five steps of hypothesis testing and explain the procedure and logic of each.
1. If two independent samples are used in a hypothesis test concerning the difference between population means for which the combined degrees of freedom is 20, which of the following could not be true about the sample sizes n1 and n2? A) n1=12 and n2=8 B) n1=12 and n2=10 C) n1=13 and n2=9 D) Cannot be determined from the giv
The city of Denver wishes to see if there is a linear relationship between temperature and the amount of electricity used (in kilowatts) Based on the data below, is there a significant linear relationship between temperature and the amount of electricity used? Temperature (x) 73 78 85 98 93 81 76 105
The data presented in the table below resulted from an experiment in which seeds of 5 different types were planted and the number of seeds that germinated within 5 weeks after planting was recorded for each seed type. At the .01 level of significance, is the proportion of seeds that germinate dependent on the seed type?
A manufacturer of flashlight batteries took a sample of 13 batteries from a day's production and used them continuously until they failed to work. The life lengths of the batteries, in hours, until they failed were: 342, 426, 317, 545, 264, 451, 1049, 631, 512, 266, 492, 562, and 298. At the .05 level of significance, is ther
An environmentalist estimates that the more waste recycled by adults in the country is more than 1 pound per person per day. You want to test this claim. You find that the mean waste recycled per person per day for a random sample of 9 adults in the country is 2 pounds and the standard deviation is 0.3 pound. At a = 0.10, can
A local chess club claims that the length of time to play a game has a mean of 49 minutes or more. Write sentences describing type I and type II errors for a hypothesis test o this claim. A Type I error will occur if the actual mean of the length of time to play a game is "pick one to insert in sentence" (less than, equal t
Write the null and alternative hypotheses. Identify which is the claim. A light bulb manufacturer claims that the mean life of a certain type of light bulb is less than 775 hours. a) Write the claim mathematically and identify Ho and Ha? b) Identify which is the claim? (choose one) The null hypothesis Ho is the
Considering that a researcher can test at the <p = .05 (95%), p = .01 (99%), or p = .001 (99.9%) level for statistical significance, how would you use these three levels in relationship to risk to patients in implementing the decisions of your research?
A random group of students was selected from a large student conference to analyze their class in school. Is there evidence to reject the hypothesis that the number of students is equally distributed between the four classes, at alpha = .05? Give the test value? Freshman = 9 Sophomores = 9 Juniors = 10 Seniors = 21
Question # 1 The critical value for this problem should have dfN and dfD of what? ANOVA TABLE Source Sum of Squares Degrees of Freedom Between 22 2 Within(error) 39 34 Total 61
Task: Use a P-value to test the claim about the population mean using the given sample statistics. State your decision for a=0.05. Claim: mean does not = 230; Sample statistics: x(bar) = 216.5, s=17.3, n=48.
Why is it said that hypothesis testing involves double negative logic? Null hypothesis could not be rejected...is this true?
1. In Meijer supermarket, the customer's waiting time to check out is approximately normally distributed with a standard deviation of 2.5 minutes. A sample of 25 customer waiting times produced a mean of 8.2 minutes. Is this evidence sufficient to reject the supermarket's claim that its customer checkout time averages no more th
I have decided to try a CRM application for its usefulness in my organizations sales department. I have 500 reps, and for my own ease, I have divided our primary area of responsibility into 4 separate divisions: North Slope, Western Coastal Villages, Eastern Border Mines, and South. I gave the sales force the CRM 3 mont
Hypothesis Testing for Proportions. 4. A flash drive manufacturer has set a standard on their production process. When defects exceed 3%, the production process is unacceptable. A random sample of 85 drives is tested. The defective rate is 5.9%. Use a level of significance of = 0.01 to test to see if you have sufficient e
Hypothesis Testing for Mean (Small Samples) 1. A local tire store suspects that the mean life of a new discount tire is less that 39,000 miles. To check the claim, the store selects randomly 18 of these new discount tires. When they are tested, it is found that the mean life is 38,250 miles with a sample standard deviation s
Hypothesis Testing for the Mean (Large Samples) 1. Use the method specified to perform the hypothesis test for the population mean . WeatherBug say that the mean daily high for December in a large Florida cit is F. WFLA weather suspects that this temperature is not accurate. A hypothesis test is performed the determine
Introduction to Hypothesis Testing State the claim mathematically. Then write the null and alternative hypothesis. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. a. A research hospital claims that more than 3.7% of the population suffers from high blood pressure. Use p, the represent
In what areas of your business is it important to draw inference? Describe a time when drawing an inference may have hurt your business. What is the significance of a one-tailed test as opposed to a two-tailed test? Describe a set of data that is one tailed. Describe a second set that is 2 tailed.
Discuss the characteristics of a good research hypothesis. What distinguishes a null hypothesis from a research hypothesis? How would you explain the difference between non-directional research and directional research hypothesis?
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, determining the ap
Exercise 3. Macaray Homes is developing two parcels near Globe Arizona. In order to test different advertising approaches, they use different media to reach potential buyers. The mean annual family income for 75 people making inquiries at the first development is $150,000, with a standard deviation of $40,000. A correspondin
1. A researcher wishes to test the claim that the average age of lifeguards in Ocean City is greater than 24 years. She selects a sample of 36 guards and finds the mean of the sample to be 24.7 years with a standard deviation of 2 years. Is there evidence to support her claim at a 95% level of confidence? 2. Consider the fo
Company W is testing a sales software. Their salesforce of 500 people is divided into four regions: Northeast, Southeast, Central and West. Each sales person is expected to sell the same amount of products. During the last 3 months, only half of the sales representatives in each region were given the software program to help the
A statewide real estate sales agency, Farm Associates, specializes in selling farm property in the state of Nebraska. Its records indicate that the mean selling time of farm property is 90 days. Because of recent drought conditions, the agency believes that the mean selling time is now greater than 90 days. A statewide survey of
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 the standard deviation of $2.14. The means appear to be very close,
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 heat attack, compared with 97 for the inactive pill. (a) State the ap