Since a t test for independent means may be used when Sample 1 and Sample 2 include different numbers of participants, the two estimates of the population variance are combined into an overall pooled estimate using a(n) __________

In the development of theory of the mind the 3-year-old child will develop an understanding of the concept of pretend before he or she understands

a. perception. c. belief. b. imagination. d. language.

How many neurons does the brain contain when the toddler is 2 years old?

a. twice as many as at birth b. four times as many as at birth c. half as many as at birth d. the same total number of neurons