1. The accompanying data on IQ for rst graders in a particular school was introduced in Example 1.2.

82 96 99 102 103 103 106 107 108 108 108 108 109 110 110 111 113 113 113 113 115 115 118 118 119 121 122 122 127 132 136 140 146

a. Calculate a point estimate of the mean value of IQ for the conceptual population of all rst graders in this school, and state which estimator you used. (Hint:  3753.)

b. Calculate a point estimate of the IQ value that separates the lowest 50% of all such students from the highest 50%, and state which estimator you used.

c. Calculate and interpret a point estimate of the population standard deviation s. Which estimator did you use? (Hint:  432,015.)

d. Calculate a point estimate of the proportion of all such students whose IQ exceeds 100.

gx2i gxi

(Hint: Think of an observation as a success if it exceeds 100.)

e. Calculate a point estimate of the population coef cient of variation s/m, and state which estimator you used.