Name:______

Statistics 108, Exam 1, Fall 2008 Name (print):______

I confirm that I am allowed only a calculator and one 3-by-5 inch note card of notes for this exam. I will not look at anybody else’s exam and I will take all necessary efforts to prevent others from seeing my exam. The consequence of using additional test aids, copying from others, or allowing others to copy my work will result in disciplinary action.

I have read and agree with the above statement. Signature: ______

  1. 4pts. Answer:______. Using the values and

, calculate . Show your work.

For the following blanks, fill in whether the random variable is

nominal,ordinal, continuous or discrete.

  1. 1pt. Answer:______The brand of automobile (Toyota, Ford, etc.)
  1. 1pt.Answer: ______Amount of pain after surgery (None, Some, Much)
  1. 1pt.Answer: ______Semester grade in a class (A,B,C,D,F)
  1. 1pt.Answer: ______Number of typographical errors in a page (0, 1, 2, etc.)

Circle whether the item is a parameter or a statistic.

  1. 1pt. statistic parameter: The mean weight of all 18 year old white men in America.
  1. 1pt. statistic parameter: The mean height of the 29 males in this class.
  1. 1pt. statistic parameter: The probability of a coin toss being heads.

The below steam-and-leaf plot shows the body temperature (in Fahrenheit) of 104 students.

Leaf Unit = 0.10

2 94 66

4 95 12

6 95 69

10 96 1334

17 96 6778999

33 97 0000011122233344

50 97 55566777888888999

(23) 98 00000001111111222233344

31 98 5555556666777889

15 99 0022233444

5 99 57

3 100 4

2 100 5

1101 4

  1. 2pts.Answer: ______How many students had body temperatures of 98.6 degrees?

The above boxplot graph shows 101 years of precipitation (rain in inches) data for Eureka and Los Angeles.

  1. 2pts.Answer:______What is the approximate median rainfall for Eureka?
  1. 2pts.Answer:______Which city has the greatest range?
  1. 2pts.Answer: ______Showing your calculations, give an estimate for the interquartile range for Eureka.

\

  1. 3pts. Answer:______El Nino years are when the water near the equator is far above normal. La Nina years are when the water near the equator is far below normal. Neutral years are when the water temperature is intermediate. Over a 101 year period, 33 years were classified as being El Nino years, 23 years as La Nina, and 45 years as neutral. If a pie chart were to be drawn, how many degrees would the La Nina slice require? Show your calculations.
  1. 2 pts. A study was performed to investigate how many miles Americans drive on a typical week day. Researchers performed a telephone survey where, on a Wednesday, they asked 200 men and 200 women about how many miles they had driven on the previous Tuesday. 50 of the 400 people were randomly selected from rural areas and the remaining people were from urban areas. Circle which of the following sampling methods was used:

(A) Systematic Sampling (B) Stratified Sampling.

  1. Using the six data values: 3, 8, 6, 4, 3, 0, calculate: (show your work)
  2. 4pts. Mean =
  1. 3pts. Median =
  1. 2pts. Mode =

  1. 2pts. Which number is the closest to the sample correlation between Age and height?

(i) -35 (ii) -1 (iii) -0.8 (iv) 0 (v) +0.8 (vi) +1 (vii) +35

  1. 2pts. Suppose the odds are 2:3 that you will win a game. What is the probability that you will win the game?
  1. Suppose a jar contains 3 black marbles and 3 white marbles. Suppose 2 marbles are randomly sampled from the jar without replacement. What is the probability of getting 1 white and 1 black marble? Show your work.

Price = 42.6 + 0.694 Salary

The above graph shows the relationship between average working salary and cost of living (Price) for 46 major cities around the world. The salaries and cost of living are scaled to where Zurich, Switzerland is 100 for both cost of living and salary. The equation for the regression line is given below the graph.

Madrid, Spain had a salary level of 50 and a Price of 93.8.

  1. 3pts. Calculate the regression line’s predicted Price for Madrid.
  1. 2pts. Calculate the residual value for Madrid.
  1. 2pts. For the Price vs. Salary scatter plot, circle the number that is closest to the correlation is:

(i) -42.6 (ii) -1 (iii) -0.8 (iv) 0 (v) +0.8 (vi) +1 (vii) +42.6

The below table shows the counts of left-handed and right-handed students and their eye colors.

Tabulated statistics: eyes, hand

Rows: eyes Columns: hand

left right All

blue 2 23 25

brown 5 22 27

green 3 12 15

All 10 57 67

Cell Contents: Count

  1. 3pts. Use the table to estimate =
  1. 3pts. Use the table to estimate

  1. 2pts. The above histogram shows precipitation amounts (inches) in Los Angeles for 101 years. The median precipitation was 13.5 inches. Compared to the median of 13.5 inches, the meanis: circle (a) more, (b) less, or (c) about the same?
  1. 2pts. In the above Venn Diagram, shade in the region represented by
  1. 2pts. In the above Venn Diagram, shade in the region represented by.

1