The average teenage girl in a sample of 200 girls texts 558 times per day with a standard deviation of 48.21. The average teenage boy in a sample of 203 boys texts 536 times per day with a standard deviation of 58.46. State a research and null hypothesis. What is the obtained Z- or t-statistic for the difference between means? Do texts per day vary by gender with an alpha value of .05 (two-tailed test)? What about .01 (two-tailed test)?