A manufacturer knows that their items have a normally distributed lifespan, with a mean of 13.1 years, and standard deviation of 3.9 years. If you randomly purchase 4 items, what is the probability that their mean life will be longer than 16 years?  Round to 4 decimal places.

A manufacturer knows that their items have a normally distributed lifespan, with a mean of 12.3 years, and standard deviation of 0.8 years. If you randomly purchase 3 items, what is the probability that their mean life will be longer than 12 years? Use GeoGebra. Round to 4 places.

The height of Christmas trees are normally distributed. The standard deviation of Christmas trees is 200 inches and the mean height is 1400 inches. What is the probability that a randomly selected Christmas tree is between 1100 and 1438 inches?

A soft drink machine outputs a mean of 29 ounces per cup. The machine's output is normally distributed with a standard deviation of 4 ounces. What is the probability of filling a cup between 25 and 31 ounces? Round your answer to four decimal places. Answer esc If you would like to look up the value in a table, select the table you want to view, then either click the cell at the intersection of the row and column or use the arrow keys to find the appropriate cell in the table and select it using the Space key. angle. 9 ! 1 9 a Z ← @ 2 W S X # 3 e d C C $ 4 r f % 5 V t Oll A 6 Normal Table - to-z Normal Table - to z b y h & 7 n O u * 8 3 O i N ( 9 k O < 1 alt ) 0 1 Р O - : Tables ; Submit Answer 4 ? 1 + = Keypad Keyboard Shortcuts 31 11 1 Oct 28 }. backspace 1 USE YOUR SMARTPHONE FOR 2:53 3 D45 enter

The time taken in the cycling phase of a triathlon has a mean 23.16min and standard deviation 8.39min. Find the probability that the mean cycling time taken by a random sample of 38 competitors is greater than 25 minutes. Give your answer in 3 decimal places.

The NJ Department of Health has reported the average life span of NJ residents is 81 years. If the standard deviation is σ = 4 years, what is the probability of a person living to at least 92 years of age?