Posted by Nora 56 on Sunday, June 2, 2013 at 7:32pm.
Sorry to repost but no one answered after I posted on the 2nd,please help,
Suppose that you are in a class of 31 students and it is assumed that approximately 13% of the population is left-handed. (Give your answers correct to three decimal places.)
(a) Compute the probability that exactly five students are left-handed.
Answer .161
(b) Compute the probability that at most four students are left-handed.
Answer .129
(c) Compute the probability that at least six students are left-handed.
Answer .193
•Math check answer - bobpursley, Sunday, June 2, 2013 at 8:19pm
a. what is .13^5 * .87^(31-5) >
Put .13^5 * .87^(31-5)= in your google search window.
b. at most four students...
add the probabliliy of one, two, three, four, and none are left handed.
Pr=.13^0*.87^31+.13^1*.87^30 + ...
c. at least six?
that is the same as 1- probability5orless
= 1- Pr(a)-Pr (b) where pr(a), pr(b) is in part a, and b.
•Math check answer - Nora 56, Thursday, June 6, 2013 at 10:01am
I worked this out like you said above and got (a)9.936 (b)9.955 and both of them were wrong, any suggestions????
Based on the information provided, it seems that there was a mistake in the calculations for parts (a) and (b) of the question. Let's go through the correct calculation steps together:
(a) To calculate the probability that exactly five students are left-handed, we use the binomial probability formula. The formula is:
P(X = k) = (n choose k) * p^k * (1-p)^(n-k)
Where:
- P(X = k) is the probability of exactly k successes
- n is the total number of trials (31 in this case)
- k is the number of successes (5 in this case)
- p is the probability of success (13%, or 0.13)
Using this formula, we can calculate the probability as follows:
P(X = 5) = (31 choose 5) * 0.13^5 * (1-0.13)^(31-5)
To calculate this, you can use a calculator or a statistical software. If you don't have access to these tools, you can also use a search engine like Google by entering the following expression in the search bar:
(31 choose 5) * 0.13^5 * (1-0.13)^(31-5)
(b) To calculate the probability that at most four students are left-handed, we need to sum the probabilities of having 0, 1, 2, 3, or 4 left-handed students. You can do this by using the same binomial probability formula and calculating each term individually. Then, you add up the results.
(c) To calculate the probability that at least six students are left-handed, you can subtract the probability of having five or fewer left-handed students from 1. So, the calculation would be:
P(X >= 6) = 1 - P(X <= 5)
By following these steps correctly, you should be able to get the correct answers for parts (a), (b), and (c) of the question.