Answer:
D.
Step-by-step explanation:
Given the assumption of a normal distribution with a mean of 100 and a standard deviation of 15, a score of 130 represents a z-score of 2. In different mostly older handbooks of descriptive statistics you can find a ‘from z to percentile-table’. Nowadays it’s more easy to use the computer. Using R, a free and open source statistical environment (www.r-project.org), you can use the command pnorm (130, 100, 15) and it will give 0.9772. Because yo want the proportion above that score you use 1-pnorm (130, 100, 15). Another way of writing in R and with for example 3 IQ-scores:
perc = pnorm (c (70, 100, 130), 100, 15)
(1 - perc)
gives you the above-proportion of the IQ-scores of respectively 70, 100 and 130.
Answer
As a decimal: 0.8
As a fraction: 4/5
Step-by-step explanation:
3/10 ÷ 3/8=
3*8=24
10*3=30
24/30= 4/5 or 0.8
Compare this function to y=ax^2 + bx + c. You can readily see that a=2, b=0 and c=6.
The x-coord. of the vertex is at x = -b / (2a). Subbing the given values for a and b, we get
x = -(0) / (2(2) = 0. At x = 0, y = 6, so the vertex of this parabola is (0,6). It opens upward.
