Severity [1] 3 1 3 2 3 0 0 0 3 3 2 3 3 1 1 1 2 0 3 3 0 1 2 0 1 3 0 3 0 3 0 3 1 2 2 4 2 [38] 3 1 1 3 3 3 3 2 1 3 3 0 1 2 3 0 3 3 3 0 0 1 3 1 0 3 3 0 1 0 3 1 0 1 3 3 0 [75] 3 3 0 3 3 2 2 2 0 1 3 3 4 3 2 3 2 0 0 3 1 3 0 2 1 3 0 2 3 0 0 0 1 0 0 1 1 [112] 0 0 3 3 1 3 3 2 1 2 0 3 1 0 3 1 3 3 1 3 3 0 0 2 2 1 3 3 0 0 1 2 3 0 0 1 2 [149] 2 3 0 0 1 0 3 3 3 3 2 2 1 2 0 0 1 1 1 3 1 3 4 2 1 2 0 1 2 1 0 1 3 3 3 3 4 [186] 0 3 3 1 4 0 0 0 0 0 1 0 0 0 0 Levels: 0 1 2 3 4 > count <- summary(Severity) > count 0 1 2 3 4 56 42 29 68 5 > prop.test(count[4],sum(count),p=.4,alternative='less',correct=FALSE) 1-sample proportions test without continuity correction data: count[4] out of sum(count), null probability 0.4 X-squared = 3, df = 1, p-value = 0.04163 alternative hypothesis: true p is less than 0.4 95 percent confidence interval: 0.0000000 0.3969047 sample estimates: p 0.34
Answer the following questions:
Why can't you use prop.test() to calculate a confidence interval using a z-distribution
This is because
The CI given by prop.test inverts the test to give a generally more accurate CI than the 'Wald score' CI in which SE is estimated by using p^ instead of p.
The Wald interval is asymptotically correct as promised, but can fail badly even for moderately large n.n. Difficulties are that it uses a normal approximation to binomial along with an estimated SE.
Interpret R code answer ABC This is a coded variable such that a value of 0 represents 'no injury', 1 represents 'possible injury', 2 represents 'no incapacity', 3 represents 'incapacity', and 4 represents 'killed'. > Severity [1] 3 1 3 2 3 0 0 0 3 3 2 3 3 1 1 1 2 0 3 3 0 1 2 0 1 3 0 3 0 3 0 3 1 2 2 4 2 [38] 3 1 1 3 3...
Question 2 12 pts Tick borne diseases are on the rise as ticks migrate to new areas of the United States. Historically, wildfire helped control tick populations. Researchers in the Southern U.S. decided to test the impact of fire on controlling the spread of lyme disease. Through coordination across several agencies, 5,000 acres of approximately contiguous forestland and rangeland is prescribe burned in late spring, with another adjacent, essentially identical 5,000 acres unburned. Over the next three years, ticks are...
(Exercise 11.1(Algorithmic)) Consider the following results for independent samples taken from two populations Sample 1 1 400 P1 0.45 Sample 2 300 p2 0.34 a. What id the point estimate of the difference between the two population proportions (to 2 decimals)i b Develop a 90% confidence interval for the difference between the two population proportions to 4 decimals to C. Develop a 95% confidence interval for the difference between the two population proportions (to 4 decimals). to Consider the hypothesis...
3. True or False? a) We use the sample proportions when to check the 4th condition when doing a hypothesis test for the difference of two population proportions. b) A 100% confidence interval for the difference of two population proportions is (0, 1). c) It is possible for p> 3 to be used as your null hypothesis when doing a hypothesis test to see if a population proportion is greater than 3. d) You find a confidence interval for the...
Consider the following results for independent samples taken from two populations. Sample 1 Sample 2 ni = 400 n2= 300 P1= 0.44 P2= 0.36 a. What is the point estimate of the difference between the two population proportions (to 2 decimals)? b. Develop a 90% confidence interval for the difference between the two population proportions (to 4 decimals). Use z-table. to c. Develop a 95% confidence interval for the difference between the two population proportions (to 4 decimals). Use z-table....
meClock Plus Home Due Sunday by 11:59pm Points 6 Submitting an external tool Available Jul 7 at 12am-Aug 2 at 11:59pm 27 days Announcements Grades Chapter 8: Confidence intervals (Proportions) Score: 0/6 0/6 answered Done Syllabus Modules Question 1 > B0/1 pt 9399 Assignments Discussions Files You are interested in constructing a 99% confidence interval for the proportion of all caterpillars that eventually become butterflies. Of the 376 randomly selected caterpillars observed, 55 lived to become butterflies. Round answers to...
- 9 of 13 ID: MST.HT.TP.01.0060 [1 point] A confidence interval is constructed for an unknown population proportion, p. A sample is collected, and the 95% confidence interval is calculated to be 0.43 + 0.05. Based on this information, it is most accurate to say that there is approximately 95% confidence in the assertion that: the population proportion is between 0.38 and 0.48 the sample proportion is between 0.38 and 0.48 the population proportion is 0.43 O the sample proportion...
Please help with these two questions? Question #1: Question #2: Consider the following results for independent samples taken from two populations. Sample 1 Sample 2 ni = 400 n2 = 200 P1 = 0.45 P2 = 0.31 a. What is the point estimate of the difference between the two population proportions (to 2 decimals)? 0.12 b. Develop a 90% confidence interval for the difference between the two population proportions (to 4 decimals). to ® c. Develop a 95% confidence interval...
1.(10) Assume that the proportion of successes in a population is p. If simple random samples of size n are drawn from the population and the proportions, p. of successes in the samples are calculated, then the distribution of the sample proportions p is normal. What are the mean and standard deviation of this Normal distribution? Hp = 2.(10) How large do the number of successes and the number of failures in a sample have to be in order to...
Run the test in SPSS. What was the t-statistic? 6.702 [1 point] What were the confidence intervals? .25, .47 [1 point] What was the p-value? 0 [1 point] PASTE YOUR SPSS OUTPUT HERE! [2 points] One-Sample Test Test Value = 0 t df Sig. (2-tailed) Mean Difference 95% Confidence Interval of the Difference Lower Upper What is your gender? 6.702 79 .000 .363 .25 .47 1. Write up your results in APA format. Your write-up should include sample mean(s)/standard deviation(s),...