For a given gestation period, the birth weights can be approximated by a normal distribution. The means and standard deviations of the birth weights for various gestation periods are shown in the table below. What percent of the babies born within each gestation period have a low birth weight (under 5.5 pounds)? (a) Under 28 weeks (b) 42 weeks and over Describe the weights of the top 10% of the babies born within each gestation period. (a) Under 28 weeks (b) 42 weeks and over  For the gestation period of 39 weeks, what is the probability that a baby will weigh between 6 and 9 pounds at birth?

For a data set of the pulse rates for a sample of adult​ females, the lowest pulse rate is 34 beats per​ minute, the mean of the listed pulse rates is x=72.0 beats per​ minute, and their standard deviation is s=13.8 beats per minute.   a. What is the difference between the pulse rate of 34 beats per minute and the mean pulse rate of the​ females? b. How many standard deviations is that​ [the difference found in part​ (a)]? c. Convert the pulse rate of 34 beats per minutes to a z score. d. If we consider pulse rates that convert to z scores between −2 and 2 to be neither significantly low nor significantly​ high, is the pulse rate of 34 beats per minute​ significant?

Suppose the durations of human pregnancies follow a mound-shaped distribution with a mean of 266 days and a standard deviation of 18 days. a. Approximately what percentage of human pregnancies last between 248 and 284 days?  b. Between what two values will the durations of 95% of all human pregnancies fall? Answer in days

For a data set of the pulse rates for a sample of adult​ females, the lowest pulse rate is 38 beats per​ minute, the mean of the listed pulse rates is x=79.0 beats per​ minute, and their standard deviation is s=22.1 beats per minute.   a. What is the difference between the pulse rate of 38 beats per minute and the mean pulse rate of the​ females? b. How many standard deviations is that​ [the difference found in part​ (a)]? c. Convert the pulse rate of 38 beats per minutes to a z score. d. If we consider pulse rates that convert to z scores between −2 and 2 to be neither significantly low nor significantly​ high, is the pulse rate of 38 beats per minute​ significant?

In nutrition, the recommended daily allowance of vitamins is a number set by the government to guide an individual's daily vitamin intake. Actually, vitamin needs vary drastically from person to person, but the needs are closely approximated by a normal curve. To calculate the recommended daily allowance, the government first finds the standard deviation and the average need for vitamins among people in the population. The recommended daily allowance is then defined as the mean plus 2.7 times the standard deviation. What fraction of the population will receive adequate amounts of vitamins under this plan? Click here to see page 1 of the table for areas under the standard normal curve. Click here to see page 2 of the table for areas under the standard normal curve. The fraction of the population that will receive adequate amounts of vitamins under the given plan is (Type an integer or decimal rounded to the nearest thousandth as needed.)

The grades for 30 students on the most recent exam are given in the data table below: Round your answer to 2 decimal places as needed 70 70 80 80 70 60 90 80 80 80 60 70 70 70 70 90 70 70 80 90 60 90 70 60 90 70 06 90 90 80 What is the mean score for the exam? What is the median score for the exam? What is the standard deviation for the exam?

In a Normal distribution, the Empirical Rule states that...       ["", "", "", "", ""]  of the data is within 1 standard deviation of the mean,       ["", "", "", "", ""]  of the data is within 2 standard deviation of the mean, and       ["", "", "", "", ""]  of the data is within 3 standard deviation of the mean.

A particular hospital's birthweight distribution is discovered to have a mean of 2700 g and a standard deviation of 200 g. Which of the following value ranges can we expect 95 percent of all birthweights at that hospital to fall within? O a. (2400, 3000) O b. (2500, 2900) O c. (2605, 2795)  d. (2600, 2800)

According to Chebyshev's Rule, at least what percent of observations must be within 2.5 standard deviations from the mean?  [a]%

In nutrition, the recommended daily allowance of vitamins is a number set by the government as a guide to an individual's daily vitamin intake. Actually, vitamin needs vary drastically from person to person, but the needs are very closely approximated by a normal curve. To calculate the recommended daily allowance, the government first finds the average need for vitamins among people in the population, and the standard deviation. The recommended daily allowance is then defined as the mean plus 2.5 times the standard deviation. What is the recommended daily allowance for a vitamin with mean u and standard deviation o? recommended daily allowance =