(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%
Answer:
12 sides
Step-by-step explanation:
To find the number of sides of a regular polygon with the sum of interior angles of 1800 degrees, we will follow the steps below;
first write down the formula for finding sum of the interior angle of a polygon
s= (n-2)180
where s is the sum of the interior angle and n is the number of side
from the question given, sum of the interior angle s=1800 degrees
substitute s=1800 degree into the formula and solve for n
s= (n-2)180
1800 = (n-2)180
divide both-side of the equation by 180
1800/180 = n-2
10 = n - 2
add 2 to both-side of the equation
10 + 2 = n
12 = n
n= 12
The polygon have 12 sides
The area of a rectangle is:
A = length × width
A rectangular television screen has an area:
A = w² + 2w inches²
width = w
length = A / width = (w² + 2w) / w = w(w + 2) / w = <u>w + 2</u>
Ansver:
<h2><u>
length = w + 2</u></h2><h2><u>
</u></h2><h2><u>
</u></h2>
Answer: Scientific knowledge?
I’m not really sure what you’re asking, but I hope this helped!
Step-by-step explanation:
