Question

Complete the following problems:

Hours	37	29	14	42	34	7	24	21	34	44	29	34	26	33	17	21	28	15	33	38
Grade	82	80	42	96	87	30	76	71	92	97	98	57	87	97	48	60	68	70	79	99

An experiment was done to determine if the amount of study hours affect the grade earned by all students in a Business class. Using the above data from the population, find the following:

Median, Mean, Range and Standard Deviation of Study Hours:

Max, Min, Interquartile Range and Variance of Grades:

Correlation Coefficient, r. Is it positive or negative correlation? What does that mean?

Construct a scatter plot of your data. Using a Regression Analysis, what grade would you expect if you studied for 40 hours?

Answer 1

Median, Mean, Range and Standard Deviation of Study Hours:

Ans: Median=29, Mean=28, Range=37 and Standard Deviation=9.84

Max, Min, Interquartile Range and Variance of Grades:

Ans: Max=99, Min=30, Interquartile Range=33 and Variance=402.69

Pearson correlation of Hours and Grade = 0.813, it is a positive correlation. This means that increase the value of  Study Hours increases the value of Grades or vice versa.

The scatter plot of data.

The regression equation is
Grade = 29.38 + 1.66 Hours

The expected grade for 40 hours study   29.38 + 1.66 *40=95.73.