# sa3 t3 6.2 7 9.12 • Name:

Age CULs Freq Rel Freq p(x) x * p(x)
4 5987 0.12 0.49
9 5746 0.12 1.06
14 6055 0.12 1.74
19 5909 0.12 2.31
24 4597 0.09 2.27
29 3695 0.08 2.20
34 3134 0.06 2.19
39 2700 0.06 2.16
44 2468 0.05 2.23
49 2313 0.05 2.33
54 1953 0.04 2.17
59 1577 0.03 1.91
64 1023 0.02 1.35
69 511 0.01 0.72
74 425 0.01 0.65
79 558 0.01 0.91
Sums: 48651 1.00 26.7

## Part I: 6.2

The frequency table on the right presents preliminary data from the 2010 FSM census for Chuuk state. The class width is five years, the number of residents in Chuuk is reported for each five year class. For part one, use this table.

1. _________ Determine the sample size n for the data.
2. _________ Determine the estimated mean age for the data.

## Part II: 7

On All Hallows Evening seventy groups of children came to the house to ask for candy. A study of the number of children per group showed that for the sample size n of 70 groups, the mean number of children per group x was 4.9 with a standard deviation sx of 4.2. For the purposes of this test, pretend that the data is continuous data and that the data is normally distributed. Use the functions of chapter seven to solve the following questions.

1. p(x ≤ 4) = _________ What percent of the groups had 4 or fewer children?
2. p(x ≥ 7) = _________ What percent of the groups had 7 or more children?
3. p(4 ≤ x ≤ 7) = _________ What percent of the groups had between 4 and 7 children?
4. p(x ≤ _________) = 0.33 Below what number of children were the smallest 33% of the groups?
5. p(x ≥ _________) = 0.33 Above what number of children were the largest 33% of the groups?

## Part III: 8 and 9.12

Use the formulas and techniques of chapters 8 and 9.12 for the following questions. Use the sample size, mean, and standard deviation from part II. Presume that the data is normally distributed.

1. SE = _________ Calculate the standard error for the mean group size.
2. Calculate the 95.45% confidence interval for the population mean μ number of children per group.

p(__________ ≤ μ ≤ __________)= 0.9545
3. _________ Toughie: Based on the above data, estimate the total number of children who came to the house.