Skip to main content
Ch. 5 - Normal Probability Distributions
Larson - Elementary Statistics: Picturing the World 8th Edition
Larson8th EditionElementary Statistics: Picturing the WorldISBN: 9780137493470당신이 사용하는 게 아니라요?교과서 변경
5장, 문제 5.5.17

Approximating a Binomial Distribution In Exercises 17 and 18, a binomial experiment is given. Determine whether you can use a normal distribution to approximate the binomial distribution. If you can, find the mean and standard deviation. If you cannot, explain why.


Bachelor’s Degrees Twenty-two percent of adults over 18 years of age have a bachelor’s degree. You randomly select 20 adults over 18 years of age and ask whether they have a bachelor’s degree.

검증된 단계별 안내
1
Step 1: Determine if the normal approximation to the binomial distribution can be used. The rule of thumb is that the normal approximation is appropriate if both np ≥ 5 and n(1-p) ≥ 5, where n is the number of trials and p is the probability of success.
Step 2: Calculate np, where n = 20 (number of trials) and p = 0.22 (probability of success). Use the formula np = n × p.
Step 3: Calculate n(1-p), where n = 20 and p = 0.22. Use the formula n(1-p) = n × (1-p).
Step 4: Check the conditions np ≥ 5 and n(1-p) ≥ 5. If both conditions are satisfied, the normal approximation can be used. If not, explain why the approximation is not valid.
Step 5: If the normal approximation is valid, calculate the mean (μ) and standard deviation (σ) of the binomial distribution. Use the formulas μ = n × p and σ = √(n × p × (1-p)).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
5m
도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Binomial Distribution

A binomial distribution models the number of successes in a fixed number of independent Bernoulli trials, each with the same probability of success. It is characterized by two parameters: n (the number of trials) and p (the probability of success on each trial). In this context, the success is defined as an adult having a bachelor's degree.
추천 영상:
03:28
Mean & Standard Deviation of Binomial Distribution

Normal Approximation to the Binomial

The normal approximation to the binomial distribution can be used when certain conditions are met, specifically when both np and n(1-p) are greater than or equal to 5. This allows for the use of the normal distribution to estimate probabilities and calculate the mean and standard deviation, simplifying analysis for larger sample sizes.
추천 영상:
06:23
Using the Normal Distribution to Approximate Binomial Probabilities

Mean and Standard Deviation of a Binomial Distribution

The mean (μ) of a binomial distribution is calculated as μ = np, while the standard deviation (σ) is given by σ = √(np(1-p)). These formulas provide essential measures of central tendency and variability, which are crucial for understanding the distribution of successes in the context of the given problem.
추천 영상:
03:28
Mean & Standard Deviation of Binomial Distribution
관련 실천
교과서 질문

Finding Area

In Exercises 23–36, find the indicated area under the standard normal curve. If convenient, use technology to find the area.


To the left of z=1.365

69
views
교과서 질문

"Getting Physical The figure shows the results of a survey of U.S. adults ages 18 to 29 who were asked whether they participated in a sport. In the survey, 48% of the men and 23% of the women said they participate in sports. The most common sports are shown below. Use this information in Exercises 29 and 30.


You randomly select 300 U.S. women ages 18 to 29 and ask them whether they participate in at least one sport. Of the 72 who say yes, 50% say they participate in volleyball. How likely is this result? Do you think this sample is a good one? Explain your reasoning."

44
views
교과서 질문

In Exercises 1–4, the sample size n, probability of success p, and probability of failure q are given for a binomial experiment. Determine whether you can use a normal distribution to approximate the distribution of x.

n=18, p=0.90, q=0.10

105
views
교과서 질문

Paint Cans A machine is set to fill paint cans with a mean of 128 ounces and a standard deviation of 0.2 ounce. A random sample of 40 cans has a mean of 127.9 ounces. The machine needs to be reset when the mean of a random sample is unusual. Does the machine need to be reset? Explain.

71
views
교과서 질문

Finding a z-Score Given an Area In Exercises 23–30, find the indicated z-score.


Find the z-score that has 78.5% of the distribution’s area to its left.

111
views
교과서 질문

Bags of Baby Carrots The weights of bags of baby carrots are normally distributed, with a mean of 32 ounces and a standard deviation of 0.36 ounce. Bags in the upper 4.5% are too heavy and must be repackaged. What is the most a bag of baby carrots can weigh and not need to be repackaged?

103
views