Sunday

April 20, 2014

April 20, 2014

Posted by **Anonymous** on Monday, November 5, 2012 at 11:07am.

- statistics -
**MathGuru**, Monday, November 5, 2012 at 6:17pmUse the normal approximation to the binomial distribution.

Mean = np = 128 * .40 = 51.2

Standard deviation = √npq = √(128 * .40 * .60) = √30.72 = 5.54

Note: q = 1 - p

Formula for z-scores:

z = (x - mean)/sd

With your data:

z = (45 - 51.2)/5.54 = -1.12

Look at a z-table for the probability using the z-score.

Double check my calculations.

I hope this will help.

**Related Questions**

statistics - According to the book Are you Normal?,40% of all US adults try to ...

statistics - According to the book Are yoy Normal?, 40% of all US adults try to ...

statistics - A normal distribution has a mean = 100. Find its standard deviation...

COLLEGE MATH - What percentage of 40 IS 120? I used the formula: 40 =x*120 -40 -...

biology - In a cross with a mother who carries the allele for hemophilia and a ...

Physics - Your 2.85kg physics book rests on a horizontal tabletop. A. Find the ...

statistics - 5. A professor teaching introductory psychology gave the grades ...

Discrete Math - Find z so that 5% of the area under the standard normal curve ...

Business Statistics - In each case, sketch the two speciﬁed normal curves...

Statistics - 1. If the mean is 40 in a normal distribution, what is the median?