Homework 1

due 09/16/14

(at the beginning of class)

Name: _______________

"Most people would sooner die than think; in fact, they do so."

––Bertrand Russell

Please turn in the answers to the following questions on separate paper. Show your work

(where appropriate)! Partial credit may save you. Please write neatly. Total = 30 points.

1.

Let's say you collect sample data from N = 11 individuals. Here they are:

Subject

(subnum)

1

2

3

4

5

6

7

8

9

10

11

Political

Conservatism

(consv)

Read the

Newspaper

(news)

1

1

2

2

3

3

3

3

4

4

5

yes no yes yes no yes no no yes no no

Use the consv data to make a frequency table (this is a 1-5 Likert scale, where 1 =

"very liberal" and 5 = "very conservative"). Include columns for political conservatism, frequency, cumulative frequency, relative frequency, and cumulative relative frequency. Confirm that the final cumulative frequency = N and that the final cumulative relative frequency = 1.0 [4]

2.

By hand, draw a frequency plot for consv. Use it to determine the probability that a randomly selected individual will be a "2" on the scale. [3]

3.

Which one of the following does not belong, and why? [2] n ∑x

i

x

µ

i =1

n

µˆ

4.

Imagine an intelligence test that has been normed to have a population mean of

100. If it is known that σ = 15 , what is the probability that a randomly selected individual will have a score less than +79.4? [2]

5.

For the following, indicate whether the scale is nominal, ordinal, interval, or ratio.

Defend your choices. [3]

Psychology 2101

Homework 1

due 09/16/14

(at the beginning of class)

Name: _______________

(a) Air pressure in a tire

(b) Your zip code

(c) The Australian Fire

Danger Rating scale →

6.

Say you collect data from participants who fill out a mood survey, in which high numbers represent relatively positive mood and low numbers represent relatively negative mood. Let's say that you knew these data were drawn from a normal distribution, and that in the population µ = 10 and σ = 1 . Given that information, before we collected any data, what was the probability that we would encounter an individual with a score at least as extreme in the negative direction as 7.38? [3]

7.

For the consv data in #1, compute the sample mean ( x ) , median, mode, sample variance ( s 2 ) (using both the computational…