The concert director can choose the new members by holding try outs to take the the possible candidate’s skills, performance and professionalism into consideration to be a part of the large show. Another way is by voting amongst other people in their school to see who the audience would be excited to see preforming in the show.
I don't know how your teacher chooses to solve this problem (or your text) but I do it this way.
Divide 81 by 3. You get 27.
Use 27 as your middle integer and go one odd integer up and down for the other 2.
25, 27, 29
the largest would be 29.
This works because 3 of the middle number equals 81, so the middle number plus a number 2 greater and a number 2 less would still be the same as adding 3 of the same number.
Check by adding the 3 numbers.
25 + 27 + 29 = 81
Answer:
a) 229 and 305 days
b) 229 days or less
c) 305 days or more
Step-by-step explanation:
The Empirical Rule(68-95-99.7 rule) states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 267
Standard deviation = 19
(a) Between what values do the lengths of the middle 95% of all pregnancies fall?_____________and___________days
By the Empirical rule, 95% of all pregnancies fall within 2 standard deviations of the mean.
So
267 - 2*19 = 229 days
to
267 + 2*19 = 305 days
(b) How short are the shortest 2.5% of all pregnancies?______days or less
95% of all pregnancies fall within 2 standard deviations of the mean. The other 5% are more than 2 standard deviations from the mean. Since the distribution is symmetric, 2.5% is more than 2 standard deviations below the mean(shortest 2.5%) and 2.5% is more than 2 standard deviations above the mean(longest 2.5%). So
267 - 2*19 = 229 days
c) How long do the longest 2.5% of pregnancies last?________days or more
Explanation in b)
267 + 2*19 = 305 days
12.73...................................
12(pi)
diameter is 4, so radius should be 2
closest height to equal 12(pi) would be 0.96
