1)Find the margin of error for the given values of C, S, and N. C=0.95, S=3.8, N=64. E=? round 3 decimal places
2)Construct the confidence interval for the population mean u. C=0.98, (x bar)=5.6, S=0.8, and n=52. A 98% confidence interval for u is? (_,_)round two decimal places
3)Construct the confidence interval for the population mean u. C=0.98, (x bar)=15.1, S=4.0, and n=65. A 98% confidence interval for u is? (_,_)round to one decimal place
4)Use the confidence interval to find the estimated margin of error. Then find the sample mean. A biologist reports a confidence interval of (1.8,2.8) when estimating the mean height(in centimeters)of a sample of seedlings. The estimated margin of error is?
5)Find the minimum sample size n needed to estimate u for the given values of c,s,and e. C=0.98, S=6.4, and E=1. Assume that a preliminary sample has at least 30 members. N=? round up to nearest whole number.
6)You are given the sample mean and the sample standard deviation. Use this info to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals. A random sample of 50 home theater systems has a mean price of $112.00 and standard deviation is $16.60. round two decimal places.
7)you are given the sample mean and the sample standard deviation. use this info to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? A random sample of 38 gas grills has a mean price of $636.40 and a standard deviation of $59.70. round one decimal place.
8)you are given the sample mean and the sample standard deviation. Use this info to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? A random sample of 34 eight-ounce servings of different juice drinks has a mean of 82.9 calories and standard deviation of 41.5 calories. round one decimal place
9)people were polled on how many books they read the previous year. how many subjects are needed to estimate the number of books read the previous year within one book with 99% confidence? Intitial survey results indicate that σ=19.9 books. round up to nearest whole number.
10)a doctor wants to estimate the HDL cholesterol of all 20-to29-year old females. how many subjects are needed to estimate the HDL cholesterol within 3 points with 99% confidence assuming σ=18.6? suppose the doctor would be content with 95% confidence. how does the decrease in confidence affect the sample size required? round up to nearest whole number.
11)Construct the indicated confidence interval for the population mean u using (a)a t-distribution. (b)if you had incorrectly used a normal distribution, which interval would be wider? c=0.99, (x-bar)=12.2, s=2.0, n=7. round one decimal place.
12)in the following situation, assume the random variable is normally distributed and use a normal distribution or a t-distribution to construct a 90% confidence interval for the population mean. (a)in a random sample of 10 adults from a nearby county, the mean waste generated per person per day was 4.98 pounds and the standard deviation was 1.79 pounds. (b)repeat part (a) assuming the same statistics came from a sample size of 600. round two decimal places for answers.
13)use the given confidence interval to find the margin of error and the sample proportion. (0.734,0.760). decimal or integer.
14)in a survey of 618 males ages 18-64, 399 say they have gone to the dentist in the past year. Construct 90% and 95% confidence intervals for the population proportion. interpret the results and compare the widths of the confidence intervals. round 3 decimal places.
15) in a survey of 8000 women, 5431 say they change their nail polish once a week. construct a 90% confidence interval for the population proportion of women who change their nail polish once a week. round 3 decimal places.
16)A researcher wishes to estimate, with 95% confidence, the proportion of adults who have high-speed internet access. her estimate must be accurate within 5% of the true proportion. (a) find the minimum sample size needed, using a prior study that found that 56% of the respondents said they have high-speed internet access. (b) no preliminary estimate is available. find the minimum sample size needed. round up to the nearest whole number.