a.
Construct a 90% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method.
Construct a 95% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method.
Construct a 99% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method.
a.

Answer to Problem 43E
The 90% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method is
The 95% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method is
The 99% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method is
Explanation of Solution
Calculation:
The given information is that,in a certain college 9 said that they planned to go to college after graduatingwhen 15 tenth-graders were asked.
Wilson’s interval:
For constructing a confidence interval the small-sample method is a simple approximation of very complicated interval that is, Wilson’s interval. Consider
Wilson’s confidence interval for p is given by,
Point estimate:
The point estimate
Substitute x as 9 and 15 as n in the formula,
Thus, the point estimate
For 90% confidence interval:
From the bottom row of Table A.3: Critical Values for the Student’s t Distribution, the critical value
Now, substitute
Thus, the 90% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method is
For 95% confidence interval:
From the bottom row of Table A.3: Critical Values for the Student’s t Distribution, the critical value
Now, substitute
Thus, the 95% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method is
For 99% confidence interval:
From the bottom row of Table A.3: Critical Values for the Student’s t Distribution, the critical value
Now, substitute
Thus, the 99% confidence interval for the proportion of tenth-graders who plan to attend college using Wilson’s method is
b.
Construct a 90% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method.
Construct a 95% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method.
Construct a 99% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method.
b.

Answer to Problem 43E
The 90% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method is
The 95% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method is
The 99% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method is
Explanation of Solution
Calculation:
Constructing confidence intervals for a proportion with small samples:
If x represents the number of individuals in a sample of size n that has certain characteristic and p is the population proportion, then
The adjusted sample proportion is,
The confidence interval for p is,
Substitute x as 9 and n as 15 in the formula of adjusted sample proportion,
For 90% confidence interval:
From the bottom row of Table A.3: Critical Values for the Student’s t Distribution, the critical value
Now, substitute
Thus, the 90% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method is
For 95% confidence interval:
From the bottom row of Table A.3: Critical Values for the Student’s t Distribution, the critical value
Now, substitute
Thus, the 95% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method is
For 99% confidence interval:
From the bottom row of Table A.3: Critical Values for the Student’s t Distribution, the critical value
Now, substitute
Thus, the 99% confidence interval for the proportion of tenth-graders who plan to attend college using small-sample method is
c.
Explain for which level the small-sample method is closer to Wilson’s method.
c.

Explanation of Solution
Approximation:
For Wilson’s method the small-sample method is a good approximation for all confidence levels commonly used in practice. And it is best when
From parts (a) and (b) it is observed that, the 95% confidence intervals obtained using Wilson’s method and small-sample method is same because the
Want to see more full solutions like this?
Chapter 7 Solutions
ALEKS 360 ESSENT. STAT ACCESS CARD
- a) Let X and Y be independent random variables both with the same mean µ=0. Define a new random variable W = aX +bY, where a and b are constants. (i) Obtain an expression for E(W).arrow_forwardThe table below shows the estimated effects for a logistic regression model with squamous cell esophageal cancer (Y = 1, yes; Y = 0, no) as the response. Smoking status (S) equals 1 for at least one pack per day and 0 otherwise, alcohol consumption (A) equals the average number of alcohoic drinks consumed per day, and race (R) equals 1 for blacks and 0 for whites. Variable Effect (β) P-value Intercept -7.00 <0.01 Alcohol use 0.10 0.03 Smoking 1.20 <0.01 Race 0.30 0.02 Race × smoking 0.20 0.04 Write-out the prediction equation (i.e., the logistic regression model) when R = 0 and again when R = 1. Find the fitted Y S conditional odds ratio in each case. Next, write-out the logistic regression model when S = 0 and again when S = 1. Find the fitted Y R conditional odds ratio in each case.arrow_forwardThe chi-squared goodness-of-fit test can be used to test if data comes from a specific continuous distribution by binning the data to make it categorical. Using the OpenIntro Statistics county_complete dataset, test the hypothesis that the persons_per_household 2019 values come from a normal distribution with mean and standard deviation equal to that variable's mean and standard deviation. Use signficance level a = 0.01. In your solution you should 1. Formulate the hypotheses 2. Fill in this table Range (-⁰⁰, 2.34] (2.34, 2.81] (2.81, 3.27] (3.27,00) Observed 802 Expected 854.2 The first row has been filled in. That should give you a hint for how to calculate the expected frequencies. Remember that the expected frequencies are calculated under the assumption that the null hypothesis is true. FYI, the bounderies for each range were obtained using JASP's drag-and-drop cut function with 8 levels. Then some of the groups were merged. 3. Check any conditions required by the chi-squared…arrow_forward
- Suppose that you want to estimate the mean monthly gross income of all households in your local community. You decide to estimate this population parameter by calling 150 randomly selected residents and asking each individual to report the household’s monthly income. Assume that you use the local phone directory as the frame in selecting the households to be included in your sample. What are some possible sources of error that might arise in your effort to estimate the population mean?arrow_forwardFor the distribution shown, match the letter to the measure of central tendency. A B C C Drag each of the letters into the appropriate measure of central tendency. Mean C Median A Mode Barrow_forwardA physician who has a group of 38 female patients aged 18 to 24 on a special diet wishes to estimate the effect of the diet on total serum cholesterol. For this group, their average serum cholesterol is 188.4 (measured in mg/100mL). Suppose that the total serum cholesterol measurements are normally distributed with standard deviation of 40.7. (a) Find a 95% confidence interval of the mean serum cholesterol of patients on the special diet.arrow_forward
- The accompanying data represent the weights (in grams) of a simple random sample of 10 M&M plain candies. Determine the shape of the distribution of weights of M&Ms by drawing a frequency histogram. Find the mean and median. Which measure of central tendency better describes the weight of a plain M&M? Click the icon to view the candy weight data. Draw a frequency histogram. Choose the correct graph below. ○ A. ○ C. Frequency Weight of Plain M and Ms 0.78 0.84 Frequency OONAG 0.78 B. 0.9 0.96 Weight (grams) Weight of Plain M and Ms 0.84 0.9 0.96 Weight (grams) ○ D. Candy Weights 0.85 0.79 0.85 0.89 0.94 0.86 0.91 0.86 0.87 0.87 - Frequency ☑ Frequency 67200 0.78 → Weight of Plain M and Ms 0.9 0.96 0.84 Weight (grams) Weight of Plain M and Ms 0.78 0.84 Weight (grams) 0.9 0.96 →arrow_forwardThe acidity or alkalinity of a solution is measured using pH. A pH less than 7 is acidic; a pH greater than 7 is alkaline. The accompanying data represent the pH in samples of bottled water and tap water. Complete parts (a) and (b). Click the icon to view the data table. (a) Determine the mean, median, and mode pH for each type of water. Comment on the differences between the two water types. Select the correct choice below and fill in any answer boxes in your choice. A. For tap water, the mean pH is (Round to three decimal places as needed.) B. The mean does not exist. Data table Тар 7.64 7.45 7.45 7.10 7.46 7.50 7.68 7.69 7.56 7.46 7.52 7.46 5.15 5.09 5.31 5.20 4.78 5.23 Bottled 5.52 5.31 5.13 5.31 5.21 5.24 - ☑arrow_forwardく Chapter 5-Section 1 Homework X MindTap - Cengage Learning x + C webassign.net/web/Student/Assignment-Responses/submit?pos=3&dep=36701632&tags=autosave #question3874894_3 M Gmail 品 YouTube Maps 5. [-/20 Points] DETAILS MY NOTES BBUNDERSTAT12 5.1.020. ☆ B Verify it's you Finish update: All Bookmarks PRACTICE ANOTHER A computer repair shop has two work centers. The first center examines the computer to see what is wrong, and the second center repairs the computer. Let x₁ and x2 be random variables representing the lengths of time in minutes to examine a computer (✗₁) and to repair a computer (x2). Assume x and x, are independent random variables. Long-term history has shown the following times. 01 Examine computer, x₁₁ = 29.6 minutes; σ₁ = 8.1 minutes Repair computer, X2: μ₂ = 92.5 minutes; σ2 = 14.5 minutes (a) Let W = x₁ + x2 be a random variable representing the total time to examine and repair the computer. Compute the mean, variance, and standard deviation of W. (Round your answers…arrow_forward
- The acidity or alkalinity of a solution is measured using pH. A pH less than 7 is acidic; a pH greater than 7 is alkaline. The accompanying data represent the pH in samples of bottled water and tap water. Complete parts (a) and (b). Click the icon to view the data table. (a) Determine the mean, median, and mode pH for each type of water. Comment on the differences between the two water types. Select the correct choice below and fill in any answer boxes in your choice. A. For tap water, the mean pH is (Round to three decimal places as needed.) B. The mean does not exist. Data table Тар Bottled 7.64 7.45 7.46 7.50 7.68 7.45 7.10 7.56 7.46 7.52 5.15 5.09 5.31 5.20 4.78 5.52 5.31 5.13 5.31 5.21 7.69 7.46 5.23 5.24 Print Done - ☑arrow_forwardThe median for the given set of six ordered data values is 29.5. 9 12 23 41 49 What is the missing value? The missing value is ☐.arrow_forwardFind the population mean or sample mean as indicated. Sample: 22, 18, 9, 6, 15 □ Select the correct choice below and fill in the answer box to complete your choice. O A. x= B. μεarrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman





