Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be 95% confident that the population mean is within 13 minutes of the sample mean? Assume the population standard deviation is 44 minutes. Round your final answer up to the next whole number. The researcher needs a sample of at least ____ people.

Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be 95% confident that the population mean is within 13 minutes of the sample mean? Assume the population standard deviation is 44 minutes. Round your final answer up to the next whole number. The researcher needs a sample of at least ____ people.

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

Professors A friend tells you about a recent study deal-ing with the number of years of teaching experience among current college professors. He remembers themean but can’t recall whether the standard deviation was6 months, 6 years, or 16 years. Tell him which one itmust have been, and why.
Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be 95% confident that the population mean is within 9 minutes of the sample mean? Assume the population standard deviation is 47 minutes. Round your final answer up to the next whole number. The researcher needs a sample of at least people.
Suppose that you are using independent samples to compare two population proportions. Fill in the blanks. a. The mean of all possible differences between the two sample proportions equals the_______.b. For large samples, the possible differences between the two samplel proportions have approximately a_________distribution.
Juan makes a measurement in a chemistry laboratory and records the result in his lab report. The standard deviation of students lab measurements is o= 8 milligrams. Juan repeats the measurement 2 times and records the mean x of his 2 measurements. What is the standard deviation of Juan's mean result?
Use the magnitudes (Richter scale) of the 120 earthquakes listed in the accompanying data table. Use technology to find the range, variance, and standard deviation. If another value, 8.00, is added to those listed in the data set, do the measures of variation change much? Click the icon to view the table of magnitudes. Magnitudes Without the extra data value, the range is (Type an integer or decimal rounded to three decimal places as needed.) 3.28 2.82 2.83 1.96 1.70 2.55 O 2.45 3.40 3.95 1.59 2.91 1.63 2.53 2.42 2.97 2.93 3.99 2.54 2.43 1.83 2.17 2.35 2.00 3.01 2.80 3.86 2.93 2.08 1.86 2.35 2.38 3.45 3.43 1.55 2.54 1.49 2.19 3.09 2.28 3.25 1.98 1.91 2.42 2.95 2.14 2.33 2.56 2.89 1.48 1.91 2.68 1.81 3.65 2.70 1.45 3.61 3.14 2.57 1.51 1.41 2.83 2.87 2.18 1.67 3.21 1.39 1.75 2.35 1.14 2.36 2.48 1.79 2.00 3.03 1.94 2.42 1.86 2.25 2.33 3.17 4.01 2.08 1.49 2.31 2.33 2.56 2.59 2.21 2.75 2.45 2.73 3.58 2.81 2.80 3.25 1.76 4.68 3.23 2.38 2.00 3.83 2.39 2.85 3.38 2.69 2.31 2.83 2.78 2.43 2.34…
The local ranger station tracked and tagged 2,844 adult female black bears in a national park. A random sample of 9 adult female black bears from those tagged had an average body weight of 203 pounds with standard deviation 25 pounds. Which of the following is a point estimate for the population mean weight of all female black bears that are tagged? A 9. C 25 D 203 2,844
A nurse at a local hospital is interested in estimating the birth weight of infants. How large a sample must she select if she desires to be 98% confident that the true mean is within 2 ounces of the sample mean? The population standard deviation of the birth weights is known to be 5 ounces. O A. 6 O B. 33 O C. 34 O D. 5 Click to select your answer. DELL EVD RW Op DELL
Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be 95% confident that the population mean is within 7 minutes of the sample mean? Assume the population standard deviation is 36 minutes. Round your final answer up to the next whole number. The researcher needs a sample of at least people. ol
Use the expression in the accompanying discussion of sample size to find the size of each sample if you want to estimate the difference between proportions of men and women who own smartphones. Assume that you want 90% confidence that your error is no more than 0.04. The sample should include ___ men and ___ women.
The coefficient of variation CV describes the standard deviation as a percent of the mean. Because it has no units, you can use the coefficient of variation to compare data with different units. Find the coefficient of variation for each sample data set. What can you conclude? Standard deviation CV = • 100% Mean E Click the icon to view the data sets. Data Table ..... CVneights = 71.2% (Round to the nearest tenth as needed.) Heights Weights 68 181 77 169 72 167 72 207 71 177 70 175 78 185 69 186 67 221 70 216 67 209 73 206
The ages (in years) of a random sample of shoppers at a gaming store are shown. Determine the range, mean, variance, and standard deviation of the sample data set. 1212, 1818, 2323, 1414, 1515, 1818, 1919, 1616, 1313, 1616 The range is 1111. (Simplify your answer.) The mean is 16.416.4. (Simplify your answer. Round to the nearest tenth as needed.) The variance is nothing. (Simplify your answer. Round to the nearest hundredth as needed.) The standard deviation is nothing. (Simplify your answer. Round to the nearest tenth as needed.)