On the basis of statistical findings, Ron determines that the differences between males and females on a test of spatial reasoning are not due merely to chance. If, in fact, there are no gender differences in the population, Ron will have made a:

a. Type I error.
b. Type II error.

a. Type 1 Error

Explanation:

Null Hypothesis is the hypothesis stating no significant difference between specified population means. Alternate Hypothesis is the hypothesis stating significant difference between specified population means.

Type 1 Error is rejecting a null hypothesis, when it is actually true. Type 2 Error is accepting a null hypothesis, when it is actually false.

Ron's determination that difference between males & females on spatial reasoning is not by chance i.e differences significant, states that he rejects the null hypothesis. However, in fact there is no difference between male & female in population in this regard. So, Ron has rejected Null Hypothesis, when it is actually true & hence has committed Type 1 Error.