Assume that blood pressure readings are normally distributed with a mean of 124 and a standard deviation of 6.4. If 64 people ar
e randomly selected, find the probability that their mean blood pressure will be less than 126. Round to four decimal places.
1 answer:
Answer:
99.38%
Step-by-step explanation:
We have that the mean (m) is equal to 124, the standard deviation (sd) 6.4 and the sample size (n) = 64
They ask us for P (x <126)
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 = (126 - 124) / (6.4 / (64 ^ 1/2))
z = 2.5
With the normal distribution table (attached), we have that at that value, the probability is:
P (z <2.5) = 0.9938
The probability is 99.38%
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<h3>The dimensions of the given rectangular box are:</h3><h3>L = 15.874 cm , B = 15.874 cm , H = 7.8937 cm</h3>
Step-by-step explanation:
Let us assume that the dimension of the square base = S x S
Let us assume the height of the rectangular base = H
So, the total area of the open rectangular box
= Area of the base + 4 x ( Area of the adjacent faces)
= S x S + 4 ( S x H) = S² + 4 SH ..... (1)
Also, Area of the box = S x S x H = S²H
⇒ S²H = 2000
Substituting the value of H in (1), we get:
Now, to minimize the area put :
Putting the value of S = 15.874 cm in the value of H , we get:
Hence, the dimensions of the given rectangular box are:
L = 15.874 cm
B = 15.874 cm
H = 7.8937 cm