The first answer is 3/34 sec and the second answer is 15/34 sec.
Set up a proportion for these problems. For the first question,
340/1 = 30/x
Cross multiply:
340*x = 1*30
340x = 30
Divide both sides by 340:
340x/340=30/340
x = 30/340 = 3/34
For the second question,
340/1 = 150/x
Cross multiply:
340*x = 150*1
340x=150
Divide both sides by 340:
340x/340 = 150/340
x = 150/340 = 15/34
Except (D)
because it's 25N not 0.25N
The Sample Mean of hours slept of the ten men asked is 8.4 hours.
The population Mean of hours slept of all the members of the theater group is 8.3 hours.
Since the parabola passes by the center its equation is:
y = ax². But it opens downward, that means the coefficient a is negative.
Then the equation becomes:
y = - ax², with x = 0 as its axis of symmetry.
We are given that the height is 84 ft when the opening downward is 42 ft.
That means to the (height) y, corresponds x =+21 & x=-21 (due to symmetry).
In order to calculate a let's plug y & x with their related values:
y = - ax²
84 = - a(21)²
84 = - a(441) and a = - 84/441 ↔ a = - 4/21
And the final equation is : y = -4/21. x²
