Answer:
25.5 mph
Step-by-step explanation:
So Bradley's speed can be modeled by the equation y=2x+40 where y=speed, x=time in hours after noon, and b=initial speed
So 12:15 is 15 minutes after noon, which is also 0.25 or 1/4 of an hour after noon. This is the x-value. Plug this into the equation to get his speed at 12:15
y=2(0.25)+40
y=0.5+40
y=40.5
So his speed was 40.5 at the time and since he was going 15 miles over the speed limit, the speed limit is 15 less than his speed
40.5 - 15 = 25.5
W has 1 line of symmetry- right down the middle. Nowhere else on the figure can it be reflected into symmetry.
Step-by-step explanation:
you know the area of a rectangle is length × width.
we know length = 10 m.
and we know the area = 60 m².
60 = 10×width
width = 60/10 = 6 m.
the fence is the perimeter, which is for a rectangle
2×length + 2×width
which is logical, as when you fully go around a rectangle, you have to pass the length 2 times and the width 2 times, right ?
length of fence = 2×10 + 2×6 = 20 + 12 = 32 m.
Answer:
A - (20% of A) = 80% of A + (20% of (80% of A) = 96% of A
So if A is 100:
100 - (.2 * 100) = 80 + (.2 * 80) = 96
Step-by-step explanation:
The mean of the confidence interval is (0.3775 + 0.6225) / 2 = 0.5. Therefore, the standard deviation of the proportion would have been sqrt[0.5*(1 - 0.5) / n], where n is the sample size. This expression simplifies to sqrt(0.25/n).
A 95% CI has a corresponding z = 1.96, so since the distance from 0.5 to 0.3775 (or 0.6225 to 0.5) is equal to 0.1225. Therefore, if we divide 0.1225 / 1.96 = 0.0625, we get the value of the SD, and this should be equal to sqrt(0.25/n).
0.0625 = sqrt(0.25/n)
n = 64
This means that the proportion was 0.5 and the sample size was 64.
