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Applied Statistics Assignment 
Q1. Read the article Tennessee's Class Size Study: Findings, Implications, Misconceptions (Finn & Achilles, 1999).
a. Discuss the population and sample in this study. Is the sample representative of the population?
b. Identify the independent and dependent variables in the waves of the experiment that covered participants in grades K3. (Hint: additional measures were used after the experiment ended, you do not need to include those).
c. Classify the dependent variable in the experiment as either continuous or discrete.
d. Classify the independent variable in the experiment as either continuous or discrete.
Q2. Consider the following frequency distribution:
Score

f

7

18

6

77

5

20

4

7

3

3

2

1

1

3

a. What was the sample size?
b. What percent of participants had a score of 4?
c. What is the percentile rank for a score of 5?
d. What is the score corresponding to the 80^{th} percentile?
Answer the questions 37 using R. Copy and paste code and output into document. Make sure questions are clearly labeled. Do not write answers as comments in R.
Q3. Define objects for values 10 and 2. Use the objects to compute the following:
a. 10 + 2
b. 10^{2}
c. √(10  2)
Q4. The following sample data are scores for 18 individuals on a 1  7 Likertscale:
1, 7, 5, 4, 6, 2, 3, 1, 6, 4, 5, 3, 2, 2, 1, 6, 4, 3
a. Enter the data into R as a vector. Print the vector.
b. Create an ungrouped frequency distribution.
c. Add percentage, cumulative frequency and cumulative percent.
Q5. The following sample data are scores for 18 individuals:
84, 76, 88, 86, 71, 85, 63, 76, 80, 79, 83, 66, 46, 96, 82, 73, 81, 92
a. Enter the data into R as a vector. Print the vector.
b. Create a grouped frequency distribution using 5 bins.
c. Add percentage, cumulative frequency and cumulative percent.
d. Create a histogram (number of bins do not need to match part b).
e. Describe the shape of the distribution using terminology learned in class.
Q6. Create a data frame using the two vectors created in problems (2) and (3). Print the data frame.
Q7. Consider two variables from a sample of 15 professors: the number of years since obtaining Ph.D. (time) and number of publications (pubs).
a. Import the phd.txt dataset into R and print out the dataset.
b. Calculate and report the mean, median and standard deviation for each variable.
c. Interpret each value from the previous question.
Attachment: Assignment Files.rar