The marriage rate per 1,000 populations per county has a normal distribution with mean 8.9 and standard deviation 1.7. Find the standardized values for the following marriage rates per 1, 000 per county. (a) 6.5 (b) 8.8 (с) 12.5 (d) 13.5.

The weights for newborn babies is approximately normally distributed with a mean of 6.8 pounds and a standard deviation of 1.8 pounds.Consider a group of 1400 newborn babies:1. How many would you expect to weigh between 4 and 9 pounds? 2. How many would you expect to weigh less than 7 pounds? 3. How many would you expect to weigh more than 5 pounds? 4. How many would you expect to weigh between 6.8 and 10 pounds?

To compare the dry braking distances from 30 to 0 miles per hour for two makes of automobiles, a safety engineer conducts braking tests for 35 models of Make A and 35 models of Make B. The mean braking distance for Make A is 42 feet. Assume the population standard deviation is 4.7 feet. The mean braking distance for Make B is 45 feet. Assume the population standard deviation is 4.4 feet. At a = 0.10, can the engineer support the claim that the mean braking distances are different for the two makes of automobiles? Assume the samples are random and independent, and the populations are normally distributed. Complete parts (a) rari rz (b) Find the critical value(s) and identify the rejection region(s). The critical value(s) is/are (Round to three decimal places as needed. Use a comma to separate answers as needed.)

Most people think that the​ "normal" adult body temperature is 98.6°F. In a more recent​ study, researchers reported that a more accurate figure may be 98.1°F. ​Furthermore, the standard deviation appeared to be around 0.7°F. Assume that a Normal model is appropriate.   b) What fraction of people would be expected to have body temperatures above 98.6°​F?