Sample size: 100

Population standard deviation: 5

Sample mean: 34.2

Formulate a hypothesis test to evaluate the claim. (Points : 10)

Ho: µ = 36; Ha: µ ≠ 36

Ho: µ ≥ 36; Ha: µ < 36

Ho: µ ≤ 34.2; Ha: µ > 34.2

Ho: µ > 36; Ha: µ ≤ 36

Ans. b.

H0 must always have equal sign, < 36 weeks

2. (TCO B) The Republican party is interested in studying the number of republicans that might vote in a particular congressional district. Assume that the number of voters is binomially distributed by party affiliation (either republican or not republican). If 10 people show up at the polls, determine the following:

Binomial distribution

10 | n | 0.5 | p |

X | P(X) | cumulative probability | 0 | 0.00098 | 0.00098 | 1 | 0.00977 | 0.01074 | 2 | 0.04395 | 0.05469 | 3 | 0.11719 | 0.17188 | 4 | 0.20508 | 0.37695 | 5 | 0.24609 | 0.62305 | 6 | 0.20508 | 0.82813 | 7 | 0.11719 | 0.94531 | 8 | 0.04395 | 0.98926 | 9 | 0.00977 | 0.99902 | 10 | 0.00098 | 1.00000 |

What is the probability that no more than four will be republicans? (Points : 10)

38%

12%

21%

62%

Ans. a

look at x=4, cumulative probability

3. (TCO A) Company ABC had sales per month as listed below. Using the Minitab output given, determine:

(A) Range (5 points);

(B) Median (5 points); and

(C) The range of the data that would contain 68% of the results. (5 points).

Raw data: sales/month (Millions of $)

23

45

34

34

56

67

54

34

45

56

23

19

Descriptive Statistics: Sales | Variable | Total Count | Mean | StDev | Variance | Minimum | Maximum | Range | Sales | 12 | 40.83 | 15.39 | 236.88 | 19.00 | 67.00 | 48.00 |

Stem-and-Leaf Display: Sales

Stem-and-leaf of Sales N = 12

Leaf Unit = 1.0 | 1 | 1 | 9 | 3 | 2 | 33 | 3 | 2 | | 6 |