Answer:
The probability that Albert's sample of 64 will have a mean between 13.5 and 16.5 minutes is 0.9973.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Let X the random variable that represent interest on this case, and for this case we know the distribution for X is given by:
And let
represent the sample mean, the distribution for the sample mean is given by:
On this case 
Solution to the problem
We are interested on this probability
If we apply the Z score formula to our probability we got this:
And we can find this probability on this way:
And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.
The probability that Albert's sample of 64 will have a mean between 13.5 and 16.5 minutes is 0.9973.
Answer:
4:1
Step-by-step explanation:
22/5.50
divide numerator by denominator and denominator by denominator
22/5.50=4
5.50/5.50=1
4/1 or 4:1
Answer:
V=4xr
Step-by-step explanation:
Answer: (-4,-8)
Step-by-step explanation: I got a 100% on the quiz
Answer:
B.
Step-by-step explanation:
The double cone is a cone on top of another cone. The bottom cone has the circular base on the bottom and the tip on top. The upper cone is upside down, and the two tips touch. Since the vertical plane goes through the tips of both cones, the cross section must have a shape that gets to a point at the middle of the height.
Answer: B. One triangle with the tip on top and an inverted triangle above it with the tips touching.