/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 41 According to a 2017 article in T... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

According to a 2017 article in The Washington Post, \(72 \%\) of high school seniors have a driver's license. Suppose we take a random sample of 100 high school seniors and find the proportion who have a driver's license. Find the probability that more than \(75 \%\) of the sample has a driver's license. Begin by verifying that the conditions for the Central Limit Theorem for Sample Proportions have been met.

Short Answer

Expert verified
The probability that more than 75% of high school seniors have a driver’s license is approximately 0.2514 or 25.14%.

Step by step solution

01

Verify the conditions for the Central Limit Theorem for Sample Proportions

The conditions for the Central Limit Theorem conditions for sample proportions are: \n\n1. The sampling method is simple random sampling. It is stated in the problem that we are taking a random sample of 100 high school seniors, so this condition is met. 2. The samples are independent. Since the sample size of 100 is less than 10% of all high school seniors (assuming there are more than 1,000 high school seniors), we can assume independence. 3. There are at least 10 successes and failures in the population. Since 72% of the high school seniors have driver’s licenses, it means that at least 72 out of 100 succeeded in getting a drivers license, and at least 28 out of 100 do not have a driver’s license. Hence, this condition is satisfied.
02

Calculate the mean and standard deviation

The mean of the sample proportion is equal to the population proportion, which is 0.72. The standard deviation, denoted as σ, of a sampling distribution is calculated by: \[σ = \sqrt{ \frac{p(1-p)}{n}}\] where p is the population proportion and n is the sample size. Inserting the values, we get standard deviation as: \[σ = \sqrt{\frac{0.72(1 - 0.72)}{100}} = 0.045\]
03

Calculate the Z-score

The Z-score measures how many standard deviations an observation is away from the mean. Here, we need to calculate the Z-score for the sample proportion of 0.75 (75%), which is greater than the population mean. The Z-score is calculated by: \[Z = \frac{p - P}{σ}\] where p is the sample proportion, P is population proportion and σ is standard deviation of the sample. Inserting the values, we get Z-score as: \[Z = \frac{0.75 - 0.72}{0.045} = 0.67\]
04

Find the probability

We needed to find the probability that the poprortion is more than 0.75 (ie. \(P(p>0.75)\)), which can be found by finding the area to the right of the Z-score (0.67) using Z-table or any statistics software/tool. The area to the right of z-score 0.67 is \(0.2514\), so, the probability that more than 75% of the students have a driver’s license is around 0.2514 or 25.14%.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Statistics student Hector Porath wanted to find out whether gender and the use of turn signals when driving were independent. He made notes when driving in his truck for several weeks. He noted the gender of each person that he observed and whether he or she used the turn signal when turning or changing lanes. (In his state, the law says that you must use your turn signal when changing lanes, as well as when turning.) The data he collected are shown in the table. $$\begin{array}{|l|l|l|}\hline & \text { Men } & \text { Women } \\\\\hline \text { Turn signal } & 585 & 452 \\ \hline \text { No signal } & 351 & 155 \\\\\hline & 936 & 607 \\ \hline\end{array}$$ a. What percentage of men used turn signals, and what percentage of women used them? b. Assuming the conditions are met (although admittedly this was not a random selection), find a \(95 \%\) confidence interval for the difference in percentages. State whether the interval captures 0, and explain whether this provides evidence that the proportions of men and women who use turn signals differ in the population. c. Another student collected similar data with a smaller sample size: $$\begin{array}{|l|c|c|}\hline & \text { Men } & \text { Women } \\\\\hline \text { Turn Signal } & 59 & 45 \\ \hline \text { No Signal } & 35 & 16 \\\\\hline & 94 & 61 \\ \hline\end{array}$$ First find the percentage of men and the percentage of women who used turn signals, and then, assuming the conditions are met, find a \(95 \%\) confidence interval for the difference in percentages. State whether the interval captures 0 , and explain whether this provides evidence that the percentage of men who use turn signals differs from the percentage of women who do so. d. Are the conclusions in parts \(\mathrm{b}\) and \(\mathrm{c}\) different? Explain.

A school district conducts a survey to determine whether voters favor passing a bond to fund school renovation projects. All registered voters are called. Of those called, \(15 \%\) answer the survey call. Of those who respond, \(62 \%\) say they favor passing the bond. Give a reason why the school district should be cautious about predicting that the bond will pass.

The Perry Preschool Project was created in the early 1960 s by David Weikart in Ypsilanti, Michigan. In this project, 123 African American children were randomly assigned to one of two groups: One group enrolled in the Perry Preschool, and one group did not enroll. Follow-up studies were done for decades. One research question was whether attendance at preschool had an effect on high school graduation. The table shows whether the students graduated from regular high school or not and includes girls only (Schweinhart et al. 2005). $$\begin{array}{lcc}\hline & \text { Preschool } & \text { No Preschool } \\\\\hline \text { HS Grad } & 21 & 8 \\ \text { No HS Grad } & 4 & 17\end{array}$$ a. Find the percentages that graduated for both groups, and compare them descriptively. Does this suggest that preschool was associated with a higher graduation rate? b. Which of the conditions fail so that we cannot use a confidence interval for the difference between proportions?

To determine if patrons are satisfied with performance quality, a theater surveys patrons at an evening performance by placing a paper survey inside their programs. All patrons receive a program as they enter the theater. Completed surveys are placed in boxes at the theater exits. On the evening of the survey, 500 patrons saw the performance. One hundred surveys were completed, and \(70 \%\) of these surveys indicated dissatisfaction with the performance. Should the theater conclude that patrons were dissatisfied with performance quality? Explain.

Bob Ross hosted a weekly television show, The Joy of Painting, on PBS in which he taught viewers how to paint. During each episode, he produced a complete painting while teaching viewers how they could produce a similar painting. Ross completed 30,000 paintings in his lifetime. Although it was an art instruction show, PBS estimated that only \(10 \%\) of viewers painted along with Ross during his show based on surveys of viewers. For each of the following, also identify the population and explain your choice. a. Is the number 30,000 a parameter or a statistic? b. Is the number \(10 \%\) a parameter or a statistic?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.