Answer to Question #212580 in Statistics and Probability for Tracy

Question

100, 100, 99, 98, 92, 91, 91, 90, 88, 87, 87, 85, 85, 85, 80, 79, 76, 72, 67, 66, 45

 

d)           James obtained a mark of 90 and Petrus obtained a mark of 79 for the test. How would you describe their results in relation to the mean? 

Answer 1

d)

$$mean=\mu=E(X)=\dfrac{1}{21}(100+100+99+98$$

$$+92+91+91+90+88+87+87+85$$

$$+85+85+80+79+76+72+67+66+45)$$

$$=83.95$$

James obtained a mark of 90 which is greater than the mean mark among 21 students.

Petrus obtained a mark of 79 which is less than the mean mark among 21 students.