7.62 The amount of time a bank teller spends with each customer has a population mean = 3.10 minutes and standard deviation = 0.40 minute. If a random sample of 16 customers is selected without replacement from a popu- lation of 500 customers, a. what is the probability that the mean time spent per cus- tomer is at least three minutes? b. there is an 85% chance that the sample mean is less than how many minutes?

Calculate the observed z value using a sample mean of 25, a population average of 20, and a standard error of the mean of 8.

Assume the random variable X is normally distributed, with mean u= 44 and standard deviationo = 9. Find the 13th percentile.

Assume that blood pressure readings are normally distributed with a mean of 124 and a standard deviation of 4.8. If 36 people are randomly selected, find the probability that their mean blood pressure will be less than 126. OA. 0.8615 OB. 0.8819 OC. 0.0062 O D. 0.9938 C...

With a mean of 10 and standard deviation of 5. Assume that the population data are normally distributed.  Calculate the z-score for a raw score of 5. What proportion of the distribution is equal to or less than this score?

Assume that adults have IQ scores that are normally distributed with a mean of 97.9 and a standard deviation of 24.8. Find the probability that a randomly selected adult has an IQ greater than 135.8.   The probability that a randomly selected adult from this group has an IQ greater than 135.8 is?

A population of values has a mean of 38.5 and standard deviation of 80.4. Find the probability that a sample of 247 values from this population will have a mean between 31.3 and 44.1.

Assume that adults have IQ scores that are normally distributed with a mean of 96 and a standard deviation 19.3. Find the first quartile Q1,which is the IQ score separating the bottom 25% from the top 75%. The first quartile is?