The critical value for a 95% two-tailed test is ± 1.96. 4. Draw a normal curve, mark it with z values and ages, and shade the critical region. Because it is a 2-tailed test, either a positive or a ...

"Let's think about shade as one of those critical services that a city can ... Phoenix's new shade plan comes as the region is recovering from a hot season that reported 466 heat-related deaths.