Answer:
The approximate probability that the mean of the rounded ages within 0.25 years of the mean of the true ages is P=0.766.
Step-by-step explanation:
We have a uniform distribution from which we are taking a sample of size n=48. We have to determine the sampling distribution and calculate the probability of getting a sample within 0.25 years of the mean of the true ages.
The mean of the uniform distribution is:
The standard deviation of the uniform distribution is:
The sampling distribution can be approximated as a normal distribution with the following parameters:
We can now calculate the probability that the sample mean falls within 0.25 from the mean of the true ages using the z-score:
1 3
----- = ----
5 x
In a proportion, u cross multiply. Take the denominator of the first fraction and multiply it by the numerator of the second fraction. Then take the numerator of the first fraction and multiply it by the denominator of the second fraction.
(5)(3) = (1)(x) ...now multiply
15 = x
and u will see from the answer 1/5 = 3/15 that these are equivalent fractions because that is all proportions are..they are just equivalent fractions.
Here is another one...
2/11 = x/22 .....cross multiply
(11)(x) = (22)(2)
11x = 44
x = 44/11
x = 4
2/11 = 4/22.....equivalent fractions
(-3/2,11/2) is the midpoint
B = 20+3-11
b = 12
answer is C. 12
Answer:
The value for the original mean = 32
Step-by-step explanation:
Here, we want to calculate the original value of the mean.
Let the number of samples be n
Mathematically;
mean = Total value/n
Now, we added 8 to each of values; total value added = 8 * n = 8n
Now, for the new mean of 40; we have
(Total value + 8n)/n = 40
Total value + 8n = 40n
Total value = 40n -8n
Total value = 32n
kindly recall from the beginning of the solution;
mean = Total value/n
mean = 32n/n
mean = 32
So the original value of the mean is 32