Question 3: (12 marks)
(1) The ideal diameter of wheel bearings produced in your plant is
7.7 mm. You have installed a new machine for
producing and polishing the bearings. The standard deviation of the
diameters of the bearings it produces is
0.11 mm. At 95% condence, how large a sample is needed to obtain a
margin of error of 0.01 mm?
(2) Amelia wants to estimate the mean weight of apples in her
orchard. She'll sample n apples and make a 95%
condence interval for the mean weight. She is willing to use = 15
grams as an estimate of the standard
deviation, and she wants the margin of error to be no more than 5
grams. What is the smallest approximate
sample size required to obtain the desired margin of error?
Question 3: (12 marks) (1) The ideal diameter of wheel bearings produced in your plant is...
Question 1: (12 marks) Correct to three decimal places if necessary. (1) The undergraduate GPA for students admitted to the top graduate business schools was 3.37. Assume this estimate was based on a sample of 120 students admitted to the top schools. Using past years' data, the population standard deviation can be assumed known with = 0:28. What is the 95% condence interval estimate of the mean undergraduate GPA for students admitted to the top graduate schools. (2) The Dean...
1. A random sample of 82 customers, who visited a department store, spent an average of $71 at this store. Suppose the standard deviation of expenditures at this store is O = $19. What is the e 98% confidence interval for the population mean? 2. A sample of 25 elements produced a mean of 123.4 and a standard deviation of 18.32 Assuming that the population has a normal distribution, what is the 90% confidence interval for the population mean? 3....
5) In a simple random sample of 59 electronic components produced by a certain method, the mean lifetime was 1,114 hours. Assume the component lifetimes are normally distributed with population standard deviation 55 hours. What is the upper bound of the 95% confidence interval for the mean lifetime of the components? Round to nearest integer. 6) Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to...
2. A population is known to have a standard deviation of 26.1. A sample space of 35 items has a mean of (1 point) 562. Construct a 90% confidence interval estimate of the mean of the population. 0566<p<558 0555<pバ569 O 551<H573 0561<p<563 3. While researching the cost of school lunches per week across the state, you use a sample size of 45(point) weekly lunch prices. The standard deviation is known to be 68 cents. In order to be 90% confident,...
1. Let X be a normal random variable with mean 16. If P(X < 20) 0.65, find the standard deviation o. 2. The probability that an electronic component will fail in performance is 0.2 Use the normal approximation to Binomial to find the probability that among 100 such components, (a) at least 23 will fail in performance. X 26) (b) between 18 and 26 (inclusive) will fail in performance. That is find P(18 3. If two random variables X and...
1. A C level confidence interval is described as what? (3 points) Oan interval computed from a data sample by a method that has the probability C of producing an interval containing the true value of the parameter any interval within the margin of error O an interval with a margin of error C that is also correct C% of the time Oany interval that follows the 68-95-99.7 rules Oan interval computed from a data sample that guarantees that the...
#2 please
Problem (12 points) Test at 0.05 significance level the claim in a college catalog that the mean price of a textbook at the college bookstore is less than 575. Assume that the prices of textbooks are normally distributed From a random sample of 16 textbooks, a mean of $70.41 with a standard deviation of $19.70, were obtained Problem #2 (12 points) A sample of 54 bears from Yellowstone National Park produces a mean weight of 182.91b. Assuming that...
1. In a poll, 69% of the people polled answered yes to the question "Are you in favor of the death penalty for a person convicted of murder?" The margin of error in the poll was 33%, and the estimate was made with 94% confidence. At least how many people were surveyed? 2. A simple random sample of size n is drawn. The sample mean, x overbar, is found to be 17.9,and the sample standard deviation, s, is found to...
QUESTION 1 A confidence interval is calculated by combining which two items? A. Sample Mean and Sample Standard Deviation B. Sample proportion and Sample Size C. Point Estimate and Margin of Error D. Sample Size and Level of Confidence QUESTION 2 When calculating a point estimate with qualitative data, you should be calculating a sample ____________________ for a given category. A. percentage B. mean C. standard deviation D. critical value QUESTION 3 Calculate the point estimate for this qualitative research...
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