A sample of 300 random adults living in the busy city revealed 63 of them favored increasing the highway speed imit from 55 to 65 mph, whereas 75 out of 180 rural residents favored the speed limit increase. Construct a 99% confidence interval for the difference of proportions.

PM Wed Nov 3 Stats Home Insert Draw View 8). Studies have shown that drivers who use cell phones while operating a motor passenger vehicle increase their risk of an accident. To quantify this risk, the New England Journal of Medicine (January 2, 2014) reported on the risk of a crash (or near crash) for both novice and expert drivers when using a cell phone. In a sample of 371 cases of novices using a cell phone while driving, 24 resulted in a crash (or near crash). In a sample of 1,467 cases of experts using a cell phone while driving. 67 resulted in a crash (or near crash). a). Find a 93% confidence interval for p, the true crash risk (probability) for novice drivers, also indicating the ME value. Answer: ME = b). Find a 93% confidence interval for p, the true crash risk (probability) for expert drivers, also indicating the ME value. Answer: гр, ME =

Postpartum depression and anxiety (PPD), is a common medical condition affecting mothers and their families after the birth of a baby. The CDC estimated that 18 % of women who have recently given birth suffer from PPD. However, this research only reflected self-reported cases. Therefore, one group dedicated to helping women and their families with PPD believes that the true percentage of women who suffer from PPD is much higher. The group conducts a simple random sample of 119 women who had given birth in the last year and discovers that 28 of them report having PPD. Based on this evidence, can the group claim that the true percentage of women who have PPD is greater than 18 % ? Use a 0.10 level of significance. Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Ho :p = 0.18 Ha:P 0.18 Answer E Tables E Keypad Keyboard Shortcuts O > Prev Nex © 2021 Hawkes Learning JIS A

The U.S. Energy Information Administration claimed that U.S. residential customers used an average of 10,608 kilowatt hours (kWh) of electricity this year. A local power company believes that residents in their area use more electricity on average than EIA's reported average. To test their claim, the company chooses a random sample of 187 of their customers and calculates that these customers used an average of 10,737kWh of electricity last year. Assuming that the population standard deviation is 1220kWh, is there sufficient evidence to support the power company's claim at the 0.05 level of significance?   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.