A One Sample t-test With SPSS Statistics
The data set analyzed to replicate Chapter 3 Table 1 consists of IQ (WISC-R) measurements on six hyperactive children. The question of interest is: “are hyperactive children in the school district brighter than the average student?” The mean IQ among the students is known to be 98. Thus, the null hypothesis in this situation is that the population mean for the hyperactive students is also 98.
To answer such a question we perform a one sample t-test specifying the null hypothesis as 98. Because a t-value squared with X degrees of freedom is equivalent to an F value with one numerator and X denominator degrees of freedom, our results are equivalent to those reported in the book. Recall that the observed F-value (with 1 and 5 degrees of freedom) in the book is 9, whereas our t-value (with 5 degrees of freedom) is 3.