The heights of fully grown sugar maple trees are normally distributed, with a mean of 87.5 feet and a standard deviation of 6.25
feet. Random samples of size 12 are drawn from the population. Find the probability that the mean height of the tree is less than 86 feet.
1 answer:
Answer:
20.33%
Step-by-step explanation:
We have that the mean (m) is equal to 87.5, the standard deviation (sd) 6.25 and the sample size (n) = 12
They ask us for P (x <86)
For this, the first thing is to calculate z, which is given by the following equation:
z = (x - m) / (sd / (n ^ 1/2))
We have all these values, replacing we have:
z = (86 - 87.5) / (6.25 / (12 ^ 1/2))
z = -0.83
With the normal distribution table (attached), we have that at that value, the probability is:
P (z <-0.83) = 0.2033
The probability is 20.33%
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Answer:
No. of gonjas = 52
No. of more nzemas than fantes = 78
Step-by-step explanation:
Total no. of people = 520
No. of fantes = × 520
No. of fantes = 156
No. of ewes = × 520 = 130
No. of nzemas = × 520 = 78
No. of gas = × 520 = 104
No. of gonjas = 520 - (156 + 130 + 78 + 104) = 52
No. of fantes = 156
No. of nzemas = 78
No. of more nzemas than fantes = 156 - 78 = 78
Pie chart of the following problem is shown below.
