In a random sample of 6 cell phones, the mean full retail price was $541.20 and the standard deviation was $183.00. Further research suggests that the population mean is $434.88. Does the t-value for the original sample fall between - to.99 and to.99? Assume that the population of full retail prices for cell phones is normally distributed. ... fall between - to.99 and to.99 because The t-value of t = ¹0.99 = ₁ (Round to two decimal places as needed.)

Assume that adults have IQ scores that are normally distributed with a mean of 104.8 and a standard deviation 21.9. Find the first quartile Q1​, which is the IQ score separating the bottom​ 25% from the top​75%

According to a recent report the battery life for a new line of laptop computers has a mean of 9 hours with a standard deviation of 2.4 hours.  If battery life is normally distributed what percentage of new laptops will last between 8 and 11 hours on a single charge?

The average wage for bank managers in a certain city is $91,900 per hour with a standard deviation of $24,300. What should be the hourly wage for an administrator if he/she wishes to earn less than 25% of all employees?

A half-century ago, the mean height of women in a particular country in their 20s was 63.7 inches. Assume that the heights of today's women in their 20s are approximately normally distributed with a standard deviation of 1.95 inches. If the mean height today is the same as that of a half-century ago, what percentage of all samples of 21 of today's women in their 20s have mean heights of at least 64.38 inches? About % of all samples have mean heights of at least 64.38 inches. (Round to one decimal place as needed.)

Suppose that the antenna lengths of woodlice are approximately normally distributed with a mean of 0.22 inches and a standard deviation of 0.05 inches. What proportion of woodlice have antenna lengths that are at most 0.18 inches? Round your answer to at least four decimal places.

The typical amount of sleep per night for college graduate students has a normal distribution with a mean of 5 hours. What is the standard deviation of this distribution if ​16% of students sleep more than 6.5​ hours?   A. ​-1.52   B. ​-1.55   C. 1.52   D. 1.55

A test involving 340 men ages 20 to 24 found that their blood cholesterol levels had a mean of 188 mg/dl and a standard deviation of 44.3 mg/dl. (a) Determine the z-score, to the nearest hundredth, for one of the men who had a blood cholesterol level of 215 mg/dl.   (b) The z-score for one man was  −1.57.  What was his blood cholesterol level? Round to the nearest hundredth.

A half-century ago, the mean height of women in a particular country in their 20s was 62.4 inches. Assume that the heights of today's women in their 20s are approximately normally distributed with a standard deviation of 1.67 inches. If the mean height today is the same as that of a half-century ago, what percentage of all samples of 27 of today's women in their 20s have mean heights of at least 63.02 inches? About% of all samples have mean heights of at least 63.02 inches. (Round to one decimal place as needed.)

An analyst found that the average amount of money in bank accounts at his/her bank is $2,000 with a standard deviation of $150.  What would be the variance?