Intro To Normal Distribution & Standard Normal Distribution
Normal Distributions:
Finding Probabilities
Normal Distributions :
Finding x and z values
Sampling Distributions & The Central Limit Theorem
Normal Approximations To Binomial Distributions
100
What Is The Area In The Bell Shape Curve ?
What is 1 .
100

What is the equation for finding the z-score of a normal x distribution?

z = (x - mu) / sigma

100

What formula is used to convert a z-Score to an x value?

x= zo + u

100

What are the new formulas when we are looking for a mean (Ex. we pick 5 trout instead of 1)

mu = mu

o = o/sqrt(n)

z = x bar - mu / new sigma

100

What do the following variables represent?

r, n, p, q?

r = number of success

n = number of trials

p = success

q = failure

200
Where Is u Found In The Curve ?
What is In The Center Or Middle Of The Curve
200

Suppose mu=32 and sigma=3.2. Find the probability of data that lies TO THE LEFT of x=37

.9406

200

Find z such that 8% of the standard normal curve lies TO THE RIGHT of z.

1.41

200

According to the central limit theorem, n must be greater than what number? **If the original was not stated as normal?

30

200

What check do you have to make to determine if the binomial distribution will work?

np > 5 and nq > 5

300

Which statement is true:

1. The curve is allowed to cross the horizontal axis

2. The curve is bell shaped and symmetrical

2

300

Suppose that mu=41 and sigma=3.4. Find the probability that x will lie TO THE RIGHT of 43.

0.2810

300

Find z such that 56% of the data lies between -z and z.

-2.01 and 2.01

300

What is the equation to find the standard error of a sampling distribution?

o/sqrt(n)

300

What are the equations for mu and standard deviation?

mu = np

sigma = sqrt(npq)

400
What percentage of data falls between 3 standard deviations each way?

99.7

400

What Do You Have To Do First To Find The Area Under Any Normal Curve?

First Convert values to Z-Scores

400

Find z such that 7.5% of the data lies TO THE LEFT of z.

-1.44

400

Let mu=10.2 and sigma=1.4. What is the MEAN length of 6 trout taken at random is greater than 8.5 inches?

.9986

400

Let n=25, p=0.30 and r >= 9. Find the z score and then probability that matches up with this info.

.6664

500
What percentage of data falls between 2 standard deviations to the left and 1 to the right?

47.5

500

Suppose mu=12 and sigma=1.2. Find the probability of the area between 10.5 and 14.

.8469

500

Accrotime doesn't want to make refunds for more than 11% of their watches. How long (to the nearest month) should they guarantee the period to be? 

Let o = 5 months and mu = 28months.

21.85 months = 22months

500

Let mu = 12.1 and sigma = 3.8 minutes. What is the probability that the MEAN time for 50 vehicles in the tunnel will be less than 13 minutes?

0.9525

500

Let n=500, p=0.65 and we want to test r <= 355. Find the z score and then the corresponding probability.

.9974

M
e
n
u