Answer:
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The idea being, when you run a perpendicular line to the base, from the right-angle in a right-triangle, like in this case, what you end up with is, three similar triangles, a Large triangle containing the two smaller ones, a Medium triangle and a Small one, check the picture below.
since all three are similar, we can use the proportions on the corresponding sides, as you see in the picture, the base of the triangle then will just be x + y.
2 1/2 feet can be written as 2.5 feet.
Divide the total distance by the distance per second:
15.6 feet / 2.5 feet per second = 6.24 seconds.
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