# Statistics

One-fifth of the population is left-handed. A random sample of 20 people is selected.

a) What is the probability that no more than 6 of the next 20 people are left-handed.

b) What is the probability that at least 4 of the next 20 people are left-handed.

1. 👍 0
2. 👎 0
3. 👁 126
1. Try using the binomial probability formula or the binomial probability table.
Using a binomial probability table is much easier.
For a): n = 20; x = 0, 1, 2, 3, 4, 5, 6; p = .20
When you find the probabilities for each x, add all of them together for your total probability.
For b): n = 20; x = 4 through 20; p = .20
When you find all the probabilities for each x, add all of them together for your total probability.
OR... and this is easier... you can find x = 0, 1, 2, 3. (You will already have these probabilities from part a.) Add together, then subtract from 1 for your total probability.

I hope this will help get you started.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### statistics

Data shows that 88% of the people in a certain population are right-handed. A group of 7 people from this population are selected at random. (a) What would be the expected value for the number of right-handed people in the group?

asked by Anonymous on March 22, 2011
2. ### statistics

according to data from the american medical association, 10% of us are left handed. If three people, are randomly selected find the probability that they are all left handed. If groups of 50 people are randomly selected, what is

asked by cm on May 7, 2012
3. ### Statistics

About 13% of the population is left handed. If two people are randomly selected what is the probability that both are left handed?

asked by Bridget on July 4, 2017
4. ### statistics

Data shows that 93% of the people in a certain population are right-handed. A group of 9 people from this population are selected at random. What is the probability that exactly 7 of the people in the group are right-handed? 2

asked by mark on March 21, 2011
5. ### statistics

A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. The population

asked by Cameron on June 3, 2013
6. ### statistic

suppose we wish to construct a confidence interval for a population proportion p. if we sample without replacement from a relatively small population of size N, the margin or error E is modified to include the finite population

asked by carl on April 17, 2012
7. ### Math

Left hand! right hand Female___!________ Male_____!_______ Total-18 ! 122 The incomplete table above summarizes the number of left-handed students and right-handed students by gender for the eighth grade students at Keisel Middle

asked by Mary on January 31, 2018
8. ### statistics

A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. 2. Identify the

asked by Cam on April 15, 2013
9. ### statistics

in a sample of 1000 people ,113 are left handed.the results of the sample are shown in the table.find the probability that a randomly selected person is a left handed,given that she is a woman.

asked by ron on October 4, 2011
10. ### Statistics

In a certain class 27% of the students are left-handed. suppose that a random sample of 53 students is selected. Find the mean number of left-handed students in the class. Round your answer to the nearest integer. Pls help!

asked by sam on October 1, 2015

More Similar Questions