Aim: what is the normal distribution?Do Now: Two sets of data given

1 2 2 3 3 3 4 4 4 4 5 5 5 6 6 7

1 1 1 2 2 3 4 5 6 8 9 9 9 10 10 10

1. Find the mean for both

2. Find the standard deviation for both

HW: Worksheet:

xi fi

1 1

2 2

3 3

4 4

5 3

6 2

7 1

xi fi

1 3

2 2

3 1

4 1

5 1

6 1

8 1

9 3

10 3

Frequency Table

A bell-shaped curve called the normal curveIn a normal curve, the greatest frequency occurs at a data value in the center of the distribution.

The distribution of data represented by the normal curve is called a normal distribution

This center value is the mean, μ

1 2 30123

Normal Curve

68%

95%

99.5%

1

2

3

68% of the scores fall within of the mean

95% of the scores fall within of the mean

99.5% of the scores fall within of the mean

A normal curve is divided into several sections by the standard deviations

A normal curve divided into 100%, therefore we can find the percentile of a certain score.

102.1 locates on -1.5 standard deviation or on about 7th percentile. Then the answer is choice (1)