- Questions & Answers
- Get Coins
Confidence intervals are an alternative to hypothesis testing.
As the level increases, the width increases.
The claim can be the null or alternative hypothesis.
The 95% confidence interval will be:
= x ± t*(s/√n)
= 23 ± 2.18*(2.4/√13)
= (21.55, 24.45)
(a) n = (2.576/0.03)^2*0.5*(1 - 0.5) = 1844
(b) n = (2.576/0.03)^2*0.13*(1 - 0.13) = 834
Please give me a thumbs-up if this helps you out. Thank you!
Can someone help me with these problems? Thank you. 1. True or False. (a) Confidence intervals...
Can someone explain on how to do 2 and 3 please thank you. would reject the claim. an effective way to treat Covid-19. 2. You wish to estimate, with 95% confidence, the mean time it takes to pet all of the cats at the animal shelter. You observe 13 random people and find that the average amount of time it took to pet the cats was 23 minutes with a standard deviation of 24 minutes. Assume the population is normally...
Can anyone please help me with my Confidence Intervals for Proportions homework? Thank you so much! 1. Express the confidence interval 38.6%±9%38.6%±9% in interval form. Express the answer in decimal format (do not enter as percents). 2. We wish to estimate what percent of adult residents in a certain county are parents. Out of 100 adult residents sampled, 26 had kids. Based on this, construct a 95% confidence interval for the proportion, p, of adult residents who are parents in this...
Constructing Confidence Intervals, Part 1: Estimating Proportion Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level: In a random sample of 200 college students, 110 had part-time jobs. Find the margin of error for the 98% confidence interval used to estimate, for the entire population of college students, the percentage who have part-time jobs. Round your answer to three decimal places. Please...
I really need help with my Confidence Intervals for the Mean homework, can someone please help? 1. You measure 34 dogs' weights, and find they have a mean weight of 52 ounces. Assume the population standard deviation is 10.2 ounces. Based on this, construct a 99% confidence interval for the true population mean dog weight. Give your answers as decimals, to two places ________________ ± ______________ ounces 2. Assume that a sample is used to estimate a population mean μμ....
Suppose you wish to estimate the mean of a normal population using a 95% confidence interval, and you know from prior information that σ2 ≈ 1. a. To see the effect of the sample size on the width of the confidence interval, calculate the width of the confidence interval for n = 16, 25, 49, 100, and 400. b. Plot the width as a function of sample size n on graph paper. Connect the points by a smooth curve and...
If you are constructing a confidence interval for a population mean, for the same confidence level, the width of the confidence interval will __________ as the sample size increases. Decrease Increase Stay the same Depends on the sample size
(22) The 99% confidence interval for the TRUE PROPORTION of success for a population is (0.318, 0.462). The random sample size is 300. (i) Please determine the SAMPLE proportion of success. (ii) Please determine the MARGIN FOR ERROR. (ii) Please determine the NUMBER OF SUCCESSFUL OUTCOMES. (23) The 90% confidence interval for the ACTUAL MEAN of a given population is (84, 90 ), via a "z" analysis. The random sample size is 81. (i) Please determine the (A) SAMPLE AVERAGE...
Question 1 to 11, True or False? Applied business statistics 1) The width of the confidence interval depends only on the desired level of confidence 2) When population standard deviation is unknown, sample standaird deviation is used and the interval estimation is based on values from the t- rather than the z-distribution n 3) The z value for a 98% confidence interval around the point estimate is 2.33 4) In order to construct a 90% confidence interval for the population...
Answer 23-24 You wish to estimate with 97% confidence, and within 3.5% of true population the proportion of computers that need repairs by the time the product is three years old. 23. No preliminary estimate is available, find the minimum sample size.  24. Find the minimum sample size if a previous study found 19% of computers need repairs within 3 years. [592 computers]
QUESTION 10 The width of the one-sample confidence interval for True a decreases as the sample re s ort False QUESTION 11 For which of the following experimental questions would you be most interested in the population proportion instead of the populatio a. Is the GPA of statistics students at this university higher than the national average? b. At this university, how many minutes a day do students exercise c. What is the mean GPA of statistics students at this...