Answer:
1. z = -1.91429
The z score tells us that the head circumference of the girl with the down syndrome ( 44.5 cm) is 1.91429 standard deviations below the mean or average head circumference
2. 2.7792%
Step-by-step explanation:
1. Relative to the WHO data, what is this girls z-score?
z score formula is:
z = (x-μ)/σ, where
x is the raw score = 44.5 cm
μ is the population mean = 47.18cm
σ is the population standard deviation = 1.40cm
z = 44.5 - 47.18/1.40
z = -1.91429
What does the z score tell us?
The z score tells us that the head circumference of the girl with the down syndrome ( 44.5 cm) is 1.91429 standard deviations below the mean or average head circumference
2. Using the WHO data in a normal model, what percentage of the girls has a head circumference that is smaller than the girl with Down's Syndrome?
z score = -1.91429
Probability value from Z-Table:
P(z =-1.91429) = P(x<44.5) = 0.027792
Converting to percentage = 0.027792 × 100
= 2.7792%
area of yard = 41 x 60 = 2460 square feet
walk is 4 feet wide
41-4 =37, 60-4 = 56
37*56 = 2072
2460-2072 = 388
area of walk is 388 square feet
You can only solve this by having the same base on each side. So to change 1/27, you can use 3^-3, which is then multiplied through. So the equation is:
4x-5=-3(2x+10)
4x-5=-6x-30
10x=-25
x=-2.5
