Homework Help: statistics

Posted by RAJESH on Wednesday, April 14, 2010 at 6:51am.

drawer contains 50 bolts and 150 nuts. Half of the bolts and half of the nuts are rusted. If one item is chosen at random, what is the probability that it is rusted or a bolt ? In a study to test whether there is a difference between the average height of adult females born in two different
countries, random samples yielded the following results :
n1 = 12O, X1 = 62.7 , S1 = 2.50
n2: 150, X2 : 61.8 , S2 = 2.62
where the measurements are in inches. Use 0.05 level of significance to test the difference between ti-re average heights.

statistics - PsyDAG, Wednesday, April 14, 2010 at 12:58pm
First question: one-half = 50%

"X" is typically used to stand for a raw score. If you don't have the symbol, you can write out "mean."

Z = (μ1 - μ2)/Standard error of difference between means (SEμ-μ)

SEμ-μ = √(SEμ1^2 + SEμ2^2)

SEμ = SD/√(n-1)

You are looking for z > 1.96 to reject Ho at .05 level.

I'll let you do the calculations.

Answer this Question

Related Questions

MATH - 4. 8 bolts and 6 nuts weigh 138 grams. 3 bolts and 5 nuts weigh 71 grams...
math - A bag contains 100 bolts and 300 nuts 50% of each have been rusted 1 item...
chem - a new compound composed of just Hex-Nuts and bolts is formed.A 13.7 Kg ...
chemistry - a new compound composed of just Hex-Nuts and bolts is formed.A 13.7 ...
statistics - A bag cntains 100 bolts nd 300 nuts 50% f each hv been rusted 1 ...
Chemistry - Assume that you had 15 nuts (N) and 10 bolts (B). How many N2B ...
Statistics - Find the probability that at most 5 defective bolts will be found ...
Chemistry - What are washers, nuts, and bolts made of? Aluminum, Zinc, Iron, or ...
Chemistry - a.) Assume that you had 100 nuts (N) and 75 bolts (B). How many NB ...
statistics - A random samples of 250 bolts manufactured by machine A and 200 ...

For Further Reading

First Name:
School Subject:
Answer: