Human measurements provide a rich area of application for statistical methods. The article “A Longitudinal Study of the Development of Elementary School Children’s Private Speech” (Merrill-Palmer Q., 1990: 443–463)

reported on a study of children talking to themselves (private speech). It was thought that private speech would be related to IQ, because IQ is supposed to measure mental maturity, and it was known that private speech decreases as students progress through the primary grades. The study included 33 students whose first-grade IQ scores are given here:

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 Describe the data and comment on any interesting features.