ASSIGNMENT 1 (To be submitted through the Assignment Submission Folder in iLearn)

DO NOT change or delete the questions. Compile your answers in one Microsoft Word

document (2 points will be deducted for not following this instruction).

Round your results to have 3 decimal points at the end.

Please pay careful attention to highlighted/bolded parts.

PART 1

Question 1 (5 Points) The 2006 General Social Survey asked, “What do you think is the ideal number of children for a

family to have?” the 1,097 females who responded had a median of 2, mean of 3.16, and a

standard deviation of 1.91.

a. What is the point estimate of the population mean? (1 points) b. Find the standard error of the sample mean. Show your work. (1 points) c. Compute the 95% confidence interval of the population mean and interpret it. Show your

work. (2 points)

d. Is it plausible that the population mean could be equal to 2? Explain. (1 points)

Question 2 (8 points) Using the Class Preparation dataset provided:

a. Generate a scatterplot of the two variables using Excel between the variables “y = Test Scores (percentage)” and “x = Study time (hours)”. (2 points)

i. Label this scatterplot as Scatterplot 1a. Provide an appropriate title for the chart and labels for both axes.

ii. Describe the relationship depicted on the scatterplot. b. Identify outlier/s and delete it/them (simply remove the values, do not replace with zero).

(2 points)

i. Show the new scatterplot and label as Scatterplot 1b. ii. Describe the pattern that emerges. What might this relationship imply? Be careful

not to infer cause and effect

c. Compute the Pearson’s correlation coefficient between the two variables (while outlier is deleted) and explain the correlation obtained. Refer to both the strength and direction of

the correlation in your interpretation. Include the correlation table. (2 points)

d. Calculate the correlation in terms of r-squared (coefficient of determination) and interpret the r-squared. Be careful not to infer cause and effect.(2 points)

Question 3 (5 Points) You are given data from a Student Self-efficacy Survey which includes composite variables of

Math Self-efficacy and Student Class Effort. Using this dataset:

a. Conduct a regression analysis to predict Math Self-efficacy (Y) from Student Class Effort (X) and show the regression output table. (2 points)

b. Interpret the results, address the multiple correlation coefficient (R), coefficient of determination (R-squared), and the significance level (p-value). (3 points)

Question 4: (5 Points) Mr. White wanted to find out if there was a difference in the 3rd period science TCAP scores (n =

38) versus 5th period science TCAP scores (n = 34). The data are provided to you in Excel sheet

called TCAP scores.

a. Generate summary statistics table (central tendency and variability measures) for the three samples and briefly summarize what they say. (2 points)

b. Generate a graph of the means of the two groups. Clearly label your axes, and give your figure a title. (1 points)

c. Conduct a test of significance for the difference between the mean test scores, show the table, and interpret the results. (2 points)

Question 5: (4 Points) This requires you to conduct a one-way analysis of variance.

Ms. Erin, a middle school teacher, wanted to find out if there was a difference in the achievement

of students between those who received instruction in a flipped classroom, online classroom, and

traditional face-to-face classroom. Data are given in the Flipped classroom worksheet in Excel.

a. Conduct an appropriate test to determine if there are differences among the various classroom teaching strategies and present the results of the analysis table (2 points).

b. Interpret the results, talk about the F value and the significance level (p-value). (2 points).

PART 2

Question 6: Hypothesis testing (8 Points) For this problem, collect data on any variables of interest (sample size for each of the two groups

should be about 30) and perform a two-sided significance test for comparing two independent

population means. You can also simulate your own data.

Address the following:

a. A brief introductory paragraph describing the problem. (1 points) b. Set up your framework in a null and alternative hypothesis using symbols and notation

as they are presented in the textbook. (1 points)

c. A paragraph describing how you collected the data (i.e., the number of observations, time of day, etc. Please present the raw data in a table. (1 points)

d. Create a graph of the means of the two samples using Excel. Clearly label your axes, and give your figure a title. (1 points)

e. Decide on a statistical analysis, show the analysis table, and explain the results of the analysis (calculated statistics, and p-values). (2 points)

f. Based on what you find, state your decision (whether you reject or fail to reject the H0) and conclusion (whether you have sufficient or insufficient evidence for H1). (1 points)

g. Describe how would you change the design to become dependent or related samples? (1 points)