Which condition must be satisfied for chi-square to be valid?

Is there a sex difference in running red lights? A researcher recorded traffic violations and driver sex in the table below. What is the expected frequency of female drivers who run yellow lights? 

Which of the following has r = 0.5  

A totally fictitious researcher wants to test whether there is a significant relationship between number of shih tzus owned and happiness. After analyzing the data on a sample of 50, she determines that r = 0.34. What is her calculated t score?

In regression, what is the error term?

My computer camera is turned on.

The Hardy-Weinberg equation can be used to:

Temperamental differences in humans are primarily a function of

Phylogenetic trees are useful because_______.

Which of the following is NOT capable of evolving?