FOR QUESTIONS 83 TO 90 USE THE FOLLOWING DIRECTION: A researcher theorizes that first-born children of African-American families are more intelligent than other African-American children. A sample of 50 first-born children of African-American families is found to have an average IQ of 105, while based on other studies we can assume that IQ of other African-American children is 100 on average and has standard deviation of 15. If she conducts hypothesis testing, she has to consider: one-tailed test two-tailed test one-tailed test because sample size is large two-tailed test because sample size is large