### Descriptive Research And Scale of Measurement, Random Sample – Statistics

The key terms in the these Statistic chapters include Random Sample, Correlation, Descriptive Research, Sample, Population, Positive Correlation, Researcher Tests, Scale of Measurement, Pearson Correlation, Convenience Sampling – STATS

The workers in a factory are organized into five-person teams. When conducting a work-environment survey, a researcher randomly selected 10 teams to obtain a total sample of 50 workers. The researcher used ____ sampling.

**Cluster**

Which sampling technique is most likely to result in a biased sample?

**Convenience sampling**

Dr. Ziser conducts an experiment on life satisfaction using participants above the age of 80. All people above the age of 80 would make up the ____.

**Population**

If every possible outcome is equally likely during sample selection, then the sample is said to be _____.

**Random**

What’s the scale of measurement? annual income

**Ratio**

Think of a way to measure STRESS using each of the three modalities:

self-report

observational/behavioral

physiological

**You could measure stress by self-report if you ask on a scale of 1-10 how stressed someone is. You can measure stress by observation if you keep track of how often somebody bites their nails, fidgets, or messes with their hair. Physiologically stress can be measured by taking someone’s blood pressure.**

Dr. DIY has created a new way to measure self-efficacy, and she finds that people who score high on her measure also score high on an existing standardized measure of the same construct. What’s it called when this happens?

**Concurrent validity**

Dr. Meridian has created a 50-question test to measure creativity, and she has had a group of participants complete the test. Now she’s gotta figure out the reliability of the test, so what she does is, for each participant, calculate a correlation between their score on the first 25 questions and their score on the last 25 questions. What kind of reliability is Dr. Meridian measuring?

**Split-half reliability**

In order to facilitate independent random sampling, ____ must be utilized.

**Sampling with replacement**

Marty is a principal who needs to contact the highest performing 15% of students in his school’s current graduating class about an opportunity to join the school’s academic honor society. At his school, students’ grade point averages is a normally distributed variable. Marty should contact students who have a grade point average that correspond with a z-score greater than or equal to _____.

**z = +1.04.**

The workers in a factory are organized into five-person teams. When conducting a work-environment survey, a researcher randomly selected 10 teams to obtain a total sample of 50 workers. The researcher used ____ sampling.

**Cluster**

Which sampling technique is most likely to result in a biased sample?

**Convenience sampling**

Dr. Ziser conducts an experiment on life satisfaction using participants above the age of 80. All people above the age of 80 would make up the ____.

**Population**

If every possible outcome is equally likely during sample selection, then the sample is said to be _____.

**Random**

What’s the scale of measurement? annual income

What is the probability of randomly selecting a z-score less than z = +2.25 from a normal distribution?

**p = 0.9878 (body)**

To avoid having her hours cut back at work, Bridgett must avoid performing in the lowest 40% of the distribution of workers at her job. Specifically, typical amount of items manufactured at her job form a normal distribution with µ = 100 and σ = 4. Bridgett needs to manufacture more than _____ items in order to avoid having her hours cut back at work.

**X = 99**

A population of N = 5 scores has a variance of σ 2 = 24. If the scores were from a sample, what value would be obtained for the sample variance?

**s2 = 30**

All the possible samples of n = 4 scores are selected from a population with µ = 20. If the average for all of the sample means is calculated, which value will be obtained?

**20**

In a population with σ = 5, a score of X = 46 corresponds to a z-score of z = +0.40. What is the population mean?

**44**

A population of scores has µ = 44. In this population, a score of X = 40 corresponds to z = -1.00. What is the population standard deviation?

**4**

What’s the goal of the descriptive research strategy?

**Describe a variable or variables as they exist naturally**

Content analysis is about observing behaviors that ____.

**Occurs in movies or tv shows**

The primary advantage of a stratified random sample is that it ____.

**Ensures that group sizes will be adequate for statistical analysis**

To select a sample of 10 employees from a factory workforce of 100, a researcher puts each employee’s name on a slip of paper, then shuffles the papers in a hat and randomly picks 10 names. What kind of sampling is being used?

**Probability**

What’s the scale of measurement? reaction time (ms)

**Ratio**

What’s the scale of measurement? IQ score

**Interval**

What’s the scale of measurement? gender (cisgender man, cisgender woman, transgender man, transgender woman)

**Nominal**

What’s the scale of measurement? years of work experience

**Ratio**

What’s the scale of measurement? SAT score

**Interval**

A set of n = 25 pairs of scores ( X and Y values) in a research study has a Pearson correlation of r = 0.80. What percentage of the variance for the Y scores is predicted by its relationship with X?

**64%**

A researcher measures driving distance from college and weekly cost of gas for a group of commuting college students. Which kind of correlation is likely to be obtained for these two variables?

**A positive correlation**

A set of n = 20 pairs of X and Y scores has SS X = 10, SS Y = 40, and SP = 30. What is the slope for the regression equation for predicting Y from X?

**b = 3.00**

A researcher obtains a Pearson correlation of r = 0.60 for a sample of n = 6 pairs of X and Y scores. If the researcher tests the significance of the correlation, which value will be obtained for the t statistic?

**t = 1.50**

A normal distribution has a mean of µ = 40 with σ = 8. If one score is randomly selected from this distribution, which is the probability that the score will be less than X = 34?

**p = 0.2266**

Which of the following is not a unique advantage of the interquartile range as measure of variability?

**The interquartile range can be used for data measured with a ratio scale of measurement.**

Which of the following characteristics tends to increase the likelihood that a clear difference between two sample means is detected statistically?

**Small variances within each sample**

The workers in a factory are organized into five-person teams. When conducting a work-environment survey, a researcher randomly selected 10 teams to obtain a total sample of 50 workers. The researcher used ____ sampling.

**Cluster**

Which sampling technique is most likely to result in a biased sample?

**Convenience sampling**

Dr. Ziser conducts an experiment on life satisfaction using participants above the age of 80. All people above the age of 80 would make up the ____.

**Population**

If every possible outcome is equally likely during sample selection, then the sample is said to be _____.

**Random**

What’s the scale of measurement? annual income

**Ratio**

What’s the scale of measurement? gender (cisgender man, cisgender woman, transgender man, transgender woman)

**Nominal**

What’s the scale of measurement? years of work experience

**Ratio**

What’s the scale of measurement? SAT score

**Interval**

A set of n = 25 pairs of scores ( X and Y values) in a research study has a Pearson correlation of r = 0.80. What percentage of the variance for the Y scores is predicted by its relationship with X?

**64%**

A researcher measures driving distance from college and weekly cost of gas for a group of commuting college students. Which kind of correlation is likely to be obtained for these two variables?

**A positive correlation**

A set of n = 20 pairs of X and Y scores has SS X = 10, SS Y = 40, and SP = 30. What is the slope for the regression equation for predicting Y from X?

**b = 3.00**