## Description

**PSY-380, section CY11/23/20, Fall 2021 ****Topic One Homework (Homework) Webassign**

**PSY-380, section CY11/23/20, Fall 2021 ****Topic One Homework (Homework) Webassign**

### Assignment Submission

For this assignment, you submit answers by question parts. The number of submissions remaining for each question part only changes if you submit or change the answer.

### Assignment Scoring

Your best submission for each question part is used for your score.

- In an experiment, researchers measure two types of variables: independent and dependent variables.

(a) Which variable is manipulated to create the groups?

(b) Which variable is measured in each group?

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- A quantitative variable varies by amount Correct: Your answer is correct. ; a qualitative variable varies by class Correct: Your answer is correct.
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- State whether each of the following words best describes descriptive statistics or inferential statistics.

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(a) describe

descriptive statistics inferential statistics

(b) infer

descriptive statistics inferential statistics

(c) summarize

descriptive statistics inferential statistics

- To determine whether a new sleeping pill was effective, adult insomniacs received a pill (either real or fake), and their sleeping times were subsequently measured (in minutes) during an overnight observation period.

- Researchers are interested in studying whether personality is related to the month in which someone was born.

(a) What scale of measurement is the month of birth?

ratio nominal ordinal interval Correct: Your answer is correct.

(b) Is it appropriate to code the data? Explain.

- State whether each of the following are continuous or discrete data.

(a) time in seconds to memorize a list of words

continuous discrete

(b) number of students in a statistics class

(c) the weight in pounds of newborn infants

(d) the SAT score among college students

- Szklarska, Koziel, Bielicki, and Malina (2007) hypothesized that taller young men are more likely to move up the scale of educational attainment compared with shorter individuals from the same social background. They recruited 91,373 nineteen-year-old men to participate in the study. Do these participants most likely represent a sample or population? Explain.

The 91,373 nineteen-year-old-men likely represent a sample of all 19-year-old men in a much larger population.

The 91,373 nineteen-year-old-men likely represent a population of 19-year-old men.

The 91,373 nineteen-year-old-men likely represent a population of men of all ages.

The 91,373 nineteen-year-old-men likely represent a sample of men of all ages in a much larger population.

- Researchers often prefer to report cumulative percents from the bottom up to explain how certain scores rank at or below other scores in a distribution. What is this type of summary called?

an open interval a percentile rank a cumulative frequency a lower boundary a distribution summary

- Below is the number of hand-washing episodes 20 patients with obsessive-compulsive disorder reported having the previous day.

12, 9, 18, …..

10, 21, 6, ……

(a) Create a simple frequency distribution for these grouped data with four intervals.

(b) Which interval had the largest frequency?

- The upper boundaries for a distribution of waiting times (in seconds) in a grocery store aisle are 46, 60, 74, and 88. List the value for each lower boundary in this distribution.
- A researcher records the number of dreams that 50 college freshman students recalled during the night prior to a final exam.

- Convert this table to a percentile rank distribution.
- What is the number of dreams at the 54th percentile?

2 dreams

- Organize the following data into a stem-and-leaf display where the following is true. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.)

247, 117, 240, 168, 112, 242, 162, 248, 243, 243

249, 113, 162, 118, 169, 115, 167, 165, 113, 160

(a) the *leaf* has one digit

- the
*stem*has one digit

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- The following is an incomplete simple frequency distribution table for the number of mistakes made during a series of military combat readiness training exercises.

Find the missing values for A, B, and C.

B = | |

C = |

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- The following bar graph summarizes the number of nights per week a sample of college students spent studying.

- How many students were observed in this study?

students(b) How many students studied 3 nights per week?

students(c) How many students studied at least 3 nights per week?

students

- Keith Rollag (2007) noticed that coworkers evaluate and treat “new” employees differently from other staff members. He was interested in how long a new employee is considered “new” in an organization. He surveyed four organizations ranging in size from 34 to 89 employees. He found that the “new” employee status was mostly reserved for the 30% of employees in the organization with the lowest tenure.

- In this study, what was the real range of employees hired by each organization surveyed?

employees(b) What was the cumulative percent of “new” employees with the lowest tenure?

%

- In February 2009, the Harris Poll asked a sample of Americans whether they thought churches and religious groups have too much or too little power and influence on Washington†. The opinions of Americans were 34% too much, 57% too little, 4% just right, and 5% unsure.

(b) Knowing that 1,010 adults were polled nationwide, how many Americans polled felt that churches and religious groups have too little power and influence on Washington? (Round your answer to the nearest whole number.)

Americans