The red blood cell counts (in millions of cells per microliter) for a population of adult males can be approximated by a normal distribution, with a mean of 5.2 million ocells per microliter and a standard deviation of 0.5 million cells per microliter. (a) What is the minimum red blood cell count that can be in the top 30% of counts? (b) What is the maximum red blood cell count that can be in the bottom 15% of counts? (a) The minimum red blood cell count is million cells per microliter. (Round to two decimal places as needed.)

Steel rods are manufactured with a mean length of 26centimeter​ (cm). Because of variability in the manufacturing​ process, the lengths of the rods are approximately normally distributed with a standard deviation of 0.05 cm. Complete parts ​(a) to ​(d). ​(a) What proportion of rods has a length less than 25.9​cm?

The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.7 days and a standard deviation of 2.1 days.What is the 80th percentile for recovery times? (Round your answer to two decimal places.)

A study of commuting times reports the travel times to work of a random sample of 1068 employed adults in Chicago. The mean is x = 54.0 minutes and the standard deviation is s = 60.9 minutes. What is the standard error of the mean?

Low-density lipoprotein, or LDL, is the main source of cholesterol buildup and blockage in the arteries. This is why LDL is known as "bad cholesterol." LDL is measured in milligrams per deciliter of blood, or mg/dL. In a population of adults at risk for cardiovascular problems, the distribution of LDL levels is normal, with a mean of 123 mg/dL and a standard deviation of 41 mg/dL. If an individual's LDL is at least 1 standard deviation or more above the mean, he or she will be monitored carefully by a doctor. What percentage of individuals from this population will have LDL levels 1 or more standard deviations above the mean? Use the 68–95–99.7 rule. (Enter your exact answer as a whole number.) percentage %