Statistics
posted by BEARHUG .
1) A Motor Company has purchased steel parts from a supplier for several years and has found that 10% of the parts must be returned because they are defective. An order of 25 parts is received. What are the mean and standard deviation of the defective parts?
A) Mean = 3.5; standard deviation = 2.5
B) Mean = 2.5; standard deviation = 1.5
C) Mean = 1.5; standard deviation = 2.5
D) Mean = 2.5; standard deviation = 3.5
2)Given a binomial random variable with n = 15 and = 0.4, find the following probability using the binomial table. P (6 < x < 10)
A) 0.0338
B) 0.1181
C) 0.0947
D) 0.3564

Statistics 
Mathguru
For 1).
Your values are the following:
p = .1, q = 1  p = .9, and n = 25
To find mean and standard deviation:
mean = np = (25)(.1) = ?
standard deviation = √npq = √(25)(.1)(.9)= ?
I'll let you finish the calculations to answer the question.
For 2).
Use the binomial table to determine your answer for the values given.
I hope this will help get you started.
Respond to this Question
Similar Questions

Math
Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts? 
math
Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts? 
math
Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts? 
Statistics/Binomal
I really need help I do not understand how to start this problem. A machine that manufactures automobile parts produces defective parts 15% of the time. If 7 parts produced by this machine are randomly selected, what is the probability … 
statistics
A shipment of 50 parts contains 12 defective parts. Suppose 3 parts are selected at random, without replacement, from the shipment. What is the probability that all 3 parts are defective? 
statistics help please :(
A shipment of 50 parts contains 11 defective parts. Suppose 3 parts are selected at random, without replacement, from the shipment. What is the probability that exactly 2 parts are not defective? 
math
im a girl ok um Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts? 
Statistics
In a shipment of 21 parts, four of the parts are defective. If three parts are selected at random without replacement, find the probability that : a.) All three parts selected are defective. 4/21*3/20*2/19=.003 b.) None of the tree … 
Statistics
A bin of 35 manufactured parts contains 6 defective parts and 29 nondefective parts. A sample of size 5 parts is selected from 35 parts. Selected parts are not replaced. How many different samples are there of size five that contain … 
Math
Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts?