PICTURE1: They are both 45
PICTURE2: 810
(a) Average time to get to school
Average time (minutes) = Summation of the two means = mean time to walk to bus stop + mean time for the bust to get to school = 8+20 = 28 minutes
(b) Standard deviation of the whole trip to school
Standard deviation for the whole trip = Sqrt (Summation of variances)
Variance = Standard deviation ^2
Therefore,
Standard deviation for the whole trip = Sqrt (2^2+4^2) = Sqrt (20) = 4.47 minutes
(c) Probability that it will take more than 30 minutes to get to school
P(x>30) = 1-P(x=30)
Z(x=30) = (mean-30)/SD = (28-30)/4.47 ≈ -0.45
Now, P(x=30) = P(Z=-0.45) = 0.3264
Therefore,
P(X>30) = 1-P(X=30) = 1-0.3264 = 0.6736 = 67.36%
With actual average time to walk to the bus stop being 10 minutes;
(d) Average time to get to school
Actual average time to get to school = 10+20 = 30 minutes
(e) Standard deviation to get to school
Actual standard deviation = Previous standard deviation = 4.47 minutes. This is due to the fact that there are no changes with individual standard deviations.
(f) Probability that it will take more than 30 minutes to get to school
Z(x=30) = (mean - 30)/Sd = (30-30)/4.47 = 0/4.47 = 0
From Z table, P(x=30) = 0.5
And therefore, P(x>30) = 1- P(X=30) = 1- P(Z=0.0) = 1-0.5 = 0.5 = 50%
I hope this helps, If there are 5 cups of flour, then there will be 7 and 1/2 cups of sugar:)
You're nearly there. Just some more steps.
557 * x = 594 tells us
x = 594 / 557 (divide both sides by 557)
x ≈ 1.066427
When we've found this number we must realise the following:
the '1' in this answer is the 100% the car fixing costs (without taxes)
the '0.66427' stands for the tax rate.
To find the tax rate we multiply 0.66427 by 100, which gives us:
0.66427 * 100 = 6.6427 ≈ 7
So, rounded to the nearest %, the tax rate is 7%
Well... the segment FG = 4x + 3, the segment GH = 7x - 12, now, the
segment FH = FG + GH, those two fellows added up, and we know that FG and GH are both equal halves because G is the midpoint.
thus, FG = GH
or
and fairly sure, you know how much that is.
