0.3x+5.14=2.1x – 4.4
2 answers:
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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.
If the largest integer drawn among the four cards is 5, then that means that 3 of the cards drawn are from the set {1, 2, 3, 4}. The number of ways of selecting 3 cards from 4 cards is given by:
If the largest integer drawn among the four cards is 6, then that means that 3 of the cards drawn are from the set {1, 2, 3, 4, 5}. The number of ways of selecting 3 cards from 5 cards is given by:
If the largest integer drawn among the four cards is 7, then that means that 3 of the cards drawn are from the set {1, 2, 3, 4, 5, 6}. The number of ways of selecting 3 cards from 6 cards is given by:
Therefore, <span>the number of selections grace could make if the largest integer drawn among the four cards is either a 5, a 6 or a 7 is given by 4 + 10 + 20 = 34 selections.</span>
If the largest integer drawn among the four cards is 6, then that means that 3 of the cards drawn are from the set {1, 2, 3, 4, 5}. The number of ways of selecting 3 cards from 5 cards is given by:
If the largest integer drawn among the four cards is 7, then that means that 3 of the cards drawn are from the set {1, 2, 3, 4, 5, 6}. The number of ways of selecting 3 cards from 6 cards is given by:
Therefore, <span>the number of selections grace could make if the largest integer drawn among the four cards is either a 5, a 6 or a 7 is given by 4 + 10 + 20 = 34 selections.</span>