Question

# I appreciate your assistance. THIS IS MY SECOND TIME POSTING THIS QUESTION. PLEASE DO NOT RESPOND...

THIS IS MY SECOND TIME POSTING THIS QUESTION. PLEASE DO NOT RESPOND IF YOU CAN NOT ANSWER THIS QUESTION CORRECTLY (WITH A FULL ANSWER). PLEASE DO NOT WRITE ON A NOTEBOOK PAGE IF I CANNOT READ YOUR HANDWRITING.

Scores on the final in a statistics class are as follows.

 75 25 75 52 80 85 80 99 90 60 86 92 40 74 72 55 87 70 85 70

a. Calculate the 25th, 50th, and 75th percentiles. (Use the methodology shown in Section 3.2 of the text to calculate the percentiles. Do not round intermediate calculations. Round your answers to 2 decimal places.)

 25th percentile 50th percentile 75.00 75th percentile

The director of graduate admissions at a local university is analyzing the relationship between scores on the Graduate Record Examination (GRE) and subsequent performance in graduate school, as measured by a student’s grade point average (GPA). She uses a sample of 10 students who graduated within the past five years.

 GRE GPA 1500 3.4 1400 3.5 1000 3.0 1050 2.9 1100 3.0 1250 3.3 800 2.7 850 2.8 950 3.2 1350 3.3

 Covariance

a-2. Interpret the covariance.

 There is relationship between GRE and GPA.

b-1. Calculate the coefficient of correlation. (Round your answer to 2 decimal places.)

 Coefficient of correlation

b-2. Does an applicant’s GRE score seem to be a good indicator of subsequent performance in graduate school?

Yes

No

a)

applying above score in an ascending order:

 s, no X 1 25 2 40 3 52 4 55 5 60 6 70 7 70 8 72 9 74 10 75 11 75 12 80 13 80 14 85 15 85 16 86 17 87 18 90 19 92 20 99

25 th percentile =(n+1)/4 th value =5.25 th value =60+0.25*(70-60)=62.5

50th  percentile =(n+1)/2 th value =10.5 th value =75

75 th  percentile =3(n+1)/4 th value =15.75 th value =85+0.75*(86-85)=85.75

a-1) covariance=57.50

a-2) There is positive relationship between GRE and GPA.

a-3) correlation =0.89

b-2) Yes (as correlation coefficient is significantly high)