Realtors of a particular county have undertaken a research study on residents of their country who are considering purchasing houses with the next 24 months. If the population proportion is assumed to be no more than 0.25, how many residents must be included in a simple random sample if the realtors want to be 99% confident that the maximum likely error will be no more than 0.015?

Suppose we know that a confidence interval for a population proportion is (0.105,0.355), with a sample proportion of p̂=0.23. What is the margin of error?

Find the mean of Binomial variable with number of trials n=5 and p=0.8

In the year 2033, katy perry is a leading traveling nurse. Katy is interested in reducing the mean recovery time for patients after experiencing a serious injury (assume recovery times are normally distributed). Suppose the mean recovery time is presently 8.6 months. Katy takes a random sample of 46 patients that have experienced serious injury to participate in a new treatment program and finds the sample mean is 8.1 months and a sample standard deviation of 1.2 months. Using α = 0.05, answer the following questions. g) What is the interpretation (not your conclusions) of the p value in the context of the problem you found in part e? h) What are your conclusions in the context of the problem? Relate your conclusions to the test statistic and critical value, confidence interval and p value.

2) The average life of a special rechargeable battery for a Calculator that performs 45 functions is 700 hours, with A standard deviation of 37 hours. A sample of 50 batteries is randomly selected, what percentage of the batteries will last more then 705 hours?

Answer the following True or False: Suppose a hypothesis test was performed with a level of significance of 0.05. Then if the null hypothesis is actually true, then there is a 5% chance that the researcher will end up accepting the alternative hypothesis in error.   false true

Solve question 9, Part A, Part B and Part C only.

Gary has discovered a new painting tool to help him in his work. If he can prove to himself that the painting tool reduces the amount of time it takes to paint a room, he has decided to invest in a tool for each of his helpers as well. From records of recent painting jobs that he completed before he got the new tool, Gary collected data for a random sample of 7 medium-sized rooms. He determined that the mean amount of time that it took him to paint each room was 3.4 hours with a standard deviation of 0.3 hours. For a random sample of 6 medium-sized rooms that he painted using the new tool, he found that it took him a mean of 3.2 hours to paint each room with a standard deviation of 0.2 hours. At the 0.05 level, can Gary conclude that his mean time for painting a medium-sized room without using the tool was greater than his mean time when using the tool? Assume that both populations are approximately normal and that the population variances are equal. Let painting times without using…

Part 1 of 4 Suppose that you randomly survey death records for people born in 1900 in Virginia and compared the life span of two different ethnicities. Of the 132 individuals sampled from ethnicity 1, the mean life span was 58.5 years with a standard deviation of 16.9 years. Of the 191 individuals sampled from ethnicity 2, the mean life span was 54.3 years with a standard deviation of 10.3 years. Conduct a hypothesis test with a 7% level of significance to see if the mean life spans in Virginia were the same for the two ethnicities. Step 1: State the null and alternative hypotheses. Ho: 12V✓0 Ha: 1₂V0 (So we will be performing a two-tailed Part 2 of 4 Step 2: Assuming the null hypothesis is true, determine the features of the distribution of the differences of sample means. The differences of sample means are t-distributed and distribution standard deviation Question Help: Post to forum C Submit Part test.) 06 ✓✓with distribution mean MacBook Pro Search or type URL ...........

A researcher takes a random sample of 100 Americans that have never had a pet and a separate random sample of 100 Americans that are current or previous pet owners. She is interested in determining whether there is a difference in the proportion of individuals who believe in the afterlife among these two groups. She observes that 76 of the "never pet owners" and 84 of the "ever pet owners" believe in the afterlife. Determine the margin of error for a confidence interval for the difference in the two appropriate proportions at a 95% confidence level. a. The assumptions necessary to perform the calculation are not satisfied. b. 0.0837 c. 0.0719 d. 0.1103 e. 1.96