Assignment 1 Descriptive Statistics (due 2/4/15-2/9/15) (13. 5 pts)

Your name ______________________________

1. 
   Some football players put streaks of black paint under their eyes because they believe that it helps them see better in sunny conditions and react more quickly. A sensory psychologist wants to see if this is really true. She gathers a group of volunteers and randomly divides them in two. Half get black paint applied under their eyes and half get flesh-color. The players are not allowed to look in the mirror, so they don’t know which color they have. The psychologist then gives them a reaction time task to measure, in milliseconds, how quickly they can respond to a change in a stimulus while bright lights are being shined at them.
   

1. 
   Generate a sentence that states the question the researcher is trying to answer (.5).
   

2. 
   Identify an independent variable (IV) and a dependent variable (DV) (.5).
   

3. 
   Determine what kind of research design is used: correlational, experimental, or quasi-experimental (.5).
   

2. 
   A neuroscientist believes that proteins form plaques in the brain that causes Alzheimer’s disease. He get a sample of older adults, measures the nanograms/lifter of protein in spinal fluid, and measures short-term memory as the percentage of words in a list that are recalled.
   

1. 
   Generate a sentence that states the question the researcher is trying to answer (.5).
   

2. 
   Identify an independent variable (IV) and a dependent variable (DV) (.5).
   

3. 
   Determine what kind of research design is used: correlational, experimental, or quasi-experimental (.5).
   

3. 
   For the following question, what level of measurement was used?
   

1. 
   The admissions committee at a college asks students to submit their SAT scores, but only on the math subtest. Subtest scores on the SAT range from a low of 200 to a high of 800, with 500 representing an average score. The SAT measures of math skills is what level of measurement? (.5)
   

2. 
   A nurse researcher measures how many minutes patients must wait before being seen by the triage nurse after they enter an emergency room. Wait time is measured at what level of measurement? (.5)
   

3. 
   A meteorologist classifies cities in the United States in terms of winter weather: “dreary” (0) or “not dreary” (1). Type of winter weather is measured at what level of measurement? (.5)
   

4. 
   A housing developer advertizes her houses as being fully carpeted (2), partially carpeted (1), or not carpeted (0). What level of measurement is amount of carpeting? (.5 pt)
   

3. 
   A survey given to a sample of 200 college students contained questions about the following variables. For each variable, identify the kind of graph that should be used to display the distribution of scores (histogram, polygon, or bar graph) (2.5).
   

1. 
   number of pizzas consumed during the previous weekend __________________
   

2. 
   size of T-shirt worn (S, M., L, XL) _____________________
   

3. 
   sex (male or female) _____________________
   

4. 
   grade point average for the previous semester _____________________
   

5. 
   college class (freshman, sophomore, junior, senior) _____________________
   

3. 
   For the following set of scores:
   

Scores: 3, 7, 6, 5, 5, 9, 6, 4, 6, 8, 10, 2, 7, 4, 9, 5, 6, 3, 8

1. 
   Construct a frequency distribution table below (1.5).
   

2. 
   Sketch a polygon showing the distribution. Do not forget to label each axis (1.5).
   

3. 
   Describe the distribution using the following characteristics (1.5):
   

1. 
   What is the shape of the distribution? ______________________
   

2. 
   What score best identifies the approximate center for the distribution? ________
   

3. 
   Are the scores clustered together, or are they spread out across the scale? ______________________
   

3. 
   For each of the following situations, identify the measure of central tendency (mean, median, or mode) that would provide the best description of the “average” score (1.5).
   

a. The college recorded the age of each student who graduated last spring. Although the majority of the students were in their early 20s, a few mature students were in their 40s and 50s: _____________________________.

Your name ______________________________

1. 
   Instructor Jill Nill has just finished teaching her first statistics class. As she breathes a sigh of relief, she notices the distribution of scores for her final exam. Below is the distribution of the exam scores (the highest possible score is 20). Consider her class as a sample.
   

Student Score (out of 20)

1 3

2 15

4 14

6 10

8 5

10 5

12 18

14 16