Answered: Obtain an 80% confidence interval for…

Math

Statistics

Obtain an 80% confidence interval for the difference in proportions of women in these two engineering fields

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

4. The lower value of a 90% confidence interval for the variance in maze-running times of a sample of 31 rats is 4.62. Based on this, form a 98% confidence interval for 02 Answer: 3.973 to 13.5219
A study was conducted by a group of neurosurgeons. They compared a dynamic system (Z-plate) and a static system (ALPS plate) in terms of the number of acute postoperative days in the hospital spent by the patients. The descriptive statistics for these data are as follows: for 14 patients with dynamic system, the sample mean number of acute postoperative days was 7.36 with standard deviation of 1.22; for 6 patients with static system the sample mean number of acute postoperative days was 10.5 with sample standard deviation of 4.59. Assume that the numbers of acute postoperative days in both populations are normally distributed. We wish to estimate µ1 − µ2 with a 99 percent confidence interval. Can you assume unknown population variance are equal. a. Degrees of freedom and t-value are b. Margin of error and confidence interval are c. Based on your interval in part (b), we can state with 99 percent confidence that the average numbers of acute postoperative days in two populations i.…
A manufacturer of MP3 players conducts a set of comprehensive tests on the electrical functions of its product. All MP3 players must pass all tests prior to being sold. Of a random sample of 900 MP3 players, 18 failed one or more tests. Find a 95% confidence interval for the proportion of MP3 players from the population that pass all tests.
Two suppliers manufacture a plastic gear used in a laser printer. The impact strength of these gears measured in foot-pounds is an important characteristic. A random sample of 10 gears from supplier 1 results in ₁ = 290 and s₁ = 12, and another random sample of 16 gears from the second supplier results in ₂ = 321 and s₂ = 22. Is there evidence to support the claim that supplier 2 provides gears with higher mean impact strength? Use a = 0.05, and assume that both populations are normally distributed but the variances are not equal. O a. Because -4.64 < -1.714, fail to reject the Null Hypothesis Ob. None among the choices O c. Reject the Null Hypothesis Od. Because -4.64 < -1.714, reject the Null Hypothesis
A school district decided to measure the BMI of all 3rd graders and identify the highest 1% and lowest 1% of those students. If the distribution is converted to a z distribution, what would be the upper critical z value and lower critical z value that mark the two significant areas at the tails?
In a previous poll, 39% of adults with children under the age of 18 reported that their family ate dinner together seven nights a week. Suppose that, in a more recent poll, 422 of 1145 adults with children under the age of 18 reported that their family ate dinner together seven nights a week. Is there sufficient evidence that the proportion of families with children under the age of 18 who eat dinner together seven nights a week has decreased? Use the x = 0.01 significance level. Because npo (1-Po) = 272.4 > 10 and the sample size is the hypothesis are satisfied. (Round to one decimal place as needed.) What are the null and alternative hypotheses? Ho: P = versus H₁: ▼ V (Type integers or decimals. Do not round.) Find the test statistic, Zo- C less than 5% of the population size, and the sample is given to be random, the requirements for testing Zo = (Round to two decimal places as needed.) Find the P-value. P-value = (Round to three decimal places as needed.) Is there sufficient…
A manufacturer of MP3 players conducts a set of comprehensive tests on the electrical functions of its product. All MP3 players must pass all tests prior to being sold. Of a random sample of 700 MP3 players, 14 failed one or more tests. Find a 99% confidence interval for the proportion of MP3 players from the population that pass all tests.
A researcher investigates whether cold medication effects mental alertness. It is known that scores on a standardized test containing a variety of problem-solving tasks are normally distributed with  = 64 and  = 8. A random sample of n = 16 teenage and a sample of n = 25 adults are given the drug and then tested. On average, the teenagers scored and average of ? = 58 and the adults scored and average of M = 65.5.a. Are the data sufficient to conclude that the medication significantly reduces mental alertness in teenagers? Test with  = .01.b. Are the data sufficient to conclude that the medication significantly increases mental alertness in adults? Test with  = .01.
In a previous poll, 37% of adults with children under the age of 18 reported that their family ate dinner together seven nights a week. Suppose that, in a more recent poll, 418 of 1183 adults with children under the age of 18 reported that their family ate dinner together seven nights a week. Is there sufficient evidence that the proportion of families with children under the age of 18 who eat dinner together seven nights a week has decreased? Use the α=0.05 significance level. Find the test statistic, z0. Find the p-value.
Two suppliers manufacture a plastic gear used in a laser printer. The impact strength of these gears measured in foot-pounds is an important characteristic. A random sample of 10 gears from supplier 1 results in ₁ = 290 and ₁ = 12, and another random sample of 16 gears from the second supplier results in ₂ = 321 and s₂ = 22. Is there evidence to support the claim that supplier 2 provides gears with higher mean impact strength? Use a = 0.05, and assume that both populations are normally distributed but the variances are not equal. a. Because -4.64 < -1.714, reject the Null Hypothesis b. Reject the Null Hypothesis c. Because -4.64 < -1.714, fail to reject the Null Hypothesis O d. None among the choices
Jelly beans are packed in boxes of 50, and the overall proportion of black jelly beans is set by the manufacturer to be 0.2. Suppose that 10 boxes of jelly beans are selected at random, and the proportion of black jelly beans in each box determined. a Use your calculator to generate 10 values of the sample proportidn p of black jelly beans in a box. b Use your calculator to find an approximate 80% confidence interval for the population proportion p from each of these values of the sample proportion p. c How many of these intervals contain the value of the population proportion p? d How many of these intervals would you expect to contain the value of the population proportion p? e Suppose that we generate 50 approximate 80% confidence intervals for p. How many of these intervals would you expect to contain the value of the population proportion p?
A random sample was selected from a population having a normal distribution. Calculate a 90% confidence interval estimate for for each of the following situations: (a). = 134, n = 10, s = 3.1 (b). = 3,744, n = 120, s = 8.2 (c). = 40.5, n = 9, = 2.9