According to a research paper, the carbon monoxide exposure of someone riding a motorbike for 5 km on a highway in a particular city is approximately normally distributed with a mean of 18.4 ppm. Suppose that the standard deviation of carbon monoxide exposure is 5.3 ppm. n USE SALT (a) Approximately what proportion of those who ride a motorbike for 5 km on a highway in this city will experience a carbon monoxide exposure of more than 20 ppm? (Round your answer to four decimal places.) (b) Approximately what proportion of those who ride a motorbike for 5 km on a highway in this city will experience a carbon monoxide exposure of more than 25 ppm? (Round your answer to four decimal places.)

Suppose that the quarterly sales levels among health care information systems companies are approximately normally distributed with a mean of 12 million dollars and a standard deviation of 1.3 million dollars. One health care information systems company considers a quarter a "failure" if its sales level that quarter is in the bottom 20% of all quarterly sales levels. Determine the sales level (in millions of dollars) that is the cutoff between quarters that are considered "failures" by that company and quarters that are not. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place. million dollars X S

Assume the average amount of caffeine consumed daily by adults is normally distributed with a mean of 260 mg and a standard deviation of 48 mg. In a random sample of 600 ​adults, how many consume at least 320 mg of caffeine​ daily?

A study showed that females’ body temperatures are approximately normally distributed with a mean of 98.40F, and a population standard deviation of 0.700F. Find the female body temperature at the 90th percentile.

For a certain type of computers, the length of time between charges of the battery is normally distributed with a mean of 62 hours and a standard deviation of 11 hours. John owns one of these computers and wants to know the number of hours when the computer would have 12%  of its battery life left. Sketch the region in question. Write a sentence describing what your answer represents about the problem's specefics.

Records indicate that the mean weight of mature rainbow trout in Eagle Creek is 1.75 kg with a standard deviation of 0.33 kg. After years of marked oxygen depletion from pollutants in the creek, a biologist wants to see if the standard deviation, o, of weights has changed. The biologist measures the weights of 20 randomly chosen mature rainbow trout from the creek and finds that the sample standard deviation is 0.38 kg. Assume the current weights of mature rainbow trout in the creek follow a normal distribution. Does the biologist have sufficient evidence to conclude that the population standard deviation, o, differs from 0.33 kg? To answer, complete the parts below to perform a hypothesis test. Use the 0.10 level of significance.

Suppose that on a certain section of I-95, with a posted speed limit of 65 miles per hour, the speeds of all vehicles have a bell-shaped distribution with a mean of 72 mph and a standard deviation of 3 mph. Find the percentage of vehicles with the following speeds on this section of I-95: greater than 75 mph.

A manufacturer of bolts has a quality control policy that requires it to destroy any bolts that are more than 2 standard deviations from the mean. The quality control engineer knows that the bolts coming off the assembly line have a mean length of 8cm with a standard deviation of 0.05 cm. For what length will a bolt be destroyed?

Suppose that blood chlorine concentration (mmol/L) has a normal distribution with mean=98 and standard deviation=7. For a sample of n=40, what is the corresponding mean and standard deviation of the sampling distribution?

Suppose the mean number of candies in a standard vending machine bag is 47.6 with a standard deviation of 1.3 . assume that the number of candies is normally distributed what percentage of bags have less than 45 candies?