Answer:
a. 81.5%
Step-by-step explanation:
The z-score for 400 is ...
Z = (X -μ)/σ = (400 -500)/100 = -1
The z-score for 700 is ...
Z = (700 -500)/100 = 2
The empirical rule tells you that 68% of the distribution is within ±1σ of the mean, and 95% is within ±2σ of the mean. Half of that first number is in the range Z = -1 to 0, and half that second number is in the range Z = 0 to +2. So, the probability you want is ...
(1/2)(68%) + (1/2)(95%) = 81.5% . . . . matches choice A
Answer:
$69.75
Step-by-step explanation:
60+0.15x is your expression.
Now, plug in 65 miles for x, as that is the changing value.
60+(0.15*65)
60+9.75
$69.75
Answer:
B. 18 cm.
Step-by-step explanation:
Because they are similar, we can say that segment AC corresponds to segment DF, and segment AB corresponds to segment ED. So, we can set up a proportion.
![\frac{16}{24} =\frac{12}{x}](https://tex.z-dn.net/?f=%5Cfrac%7B16%7D%7B24%7D%20%3D%5Cfrac%7B12%7D%7Bx%7D)
![\frac{2}{3} =\frac{12}{x}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B3%7D%20%3D%5Cfrac%7B12%7D%7Bx%7D)
2 * x = 12 * 3
2x = 36
x = 18
So, the length of ED is B. 18 cm.
Hope this helps!