Answer:
And we can find this probability using the normal standard distribution table and we got:
And the percentage faster than 13.28 seconds would be 91.9%
Step-by-step explanation:
Let X the random variable that represent the runtimes of a population, and for this case we know the distribution for X is given by:
Where 
and 
We want to find this probability:
And we can use the z score formula given by:
Using this formula we have:
And we can find this probability using the normal standard distribution table and we got:
And the percentage faster than 13.28 seconds would be 91.9%
Answer: 1/2, 1/2, 1/4
Step-by-step explanation:
To find the fraction that the hour hand turns of a clockwise revolution, we have to find how long it is going then divide by 12
Ex. a) 11 - 5 = 6, 6/12 = 1/2 so the hour hand turns by 1/2 of a clockwise revolution
b) 8 - 2 = 6, 6/12 = 1/2 so the hour hand turns by 1/2 of a clockwise revolution
c) For this, we have to convert 1 into 13 as 1 - 10 is a negative number
13 - 10 = 3, 3/12 = 1/4 so the hour hand turns by 1/4 of a clockwise revolution
D/60 + D/50 = 2D/55 - 1/2
find common denominator ( 3300)
3300/60 = 55
3300/50 = 66
3300/55=60
so then you get 55D +66D= 60(2D)-1650
121D=120D-1650
D=1650 miles
check
1650/60 =27.5, 1650/50 = 33, 27.5 + 33 = 60.5 hours total
1650/55 = 30, 30 x 2 = 60
60.5-60 = 0.5 longer
so distance = 1650 miles
