The longer sides of the rectangles should be the same value, so we can make the lower part of the equation equal to 18, which is 4.
We can even find the y value by making it equal to 10, which is 3.
(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:
C
Step-by-step explanation:
Number 4
Answer:96.97
Step-by-step explanation:
Given
mean height of women 
Standard deviation of height 
mean height of men 
Standard deviation of height 
P
P
P
i.e. 0.9697=96.97 %
f(x) increase by a factor of 3
Explanation:
Given that f(x)= 3* and the interval is x=4 to x=57
Now we put the value for x is 4 to 57 then value of f(x) increase with the multiply of 3.
Because the x is multiplied with 3 i.e., 3*
So f(x) increase by a factor of 3.
If we put x=4, then f(x)= 12 (∵ 3×4=12)
If we put x=5, the f(x)= 15 (∵ 3×5=15)
If we put x=6,the f(x)= 18 (∵ 3×6=18)
similarly., values of x= 7,8,9,...155.
Then,
If we put x=56, the f(x)=168
This process will continue until f(x)=171 for x=57.
