Answer: a. 0.6759 b. 0.3752 c. 0.1480
Step-by-step explanation:
Given : The long-distance calls made by the employees of a company are normally distributed with a mean of 6.3 minutes and a standard deviation of 2.2 minutes
i.e. 
minutes
minutes
Let x be the long-distance call length.
a. The probability that a call lasts between 5 and 10 minutes will be :-
b. The probability that a call lasts more than 7 minutes. :
![P(X>7)=P(\dfrac{X-\mu}{\sigma}>\dfrac{7-6.3}{2.2})\\\\=P(Z>0.318)\ \ \ \ [z=\dfrac{X-\mu}{\sigma}]\\\\=1-P(Z](https://tex.z-dn.net/?f=P%28X%3E7%29%3DP%28%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%3E%5Cdfrac%7B7-6.3%7D%7B2.2%7D%29%5C%5C%5C%5C%3DP%28Z%3E0.318%29%5C%20%5C%20%5C%20%5C%20%5Bz%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5D%5C%5C%5C%5C%3D1-P%28Z%3C0.318%29%5C%5C%5C%5C%3D1-0.6248%5C%20%5C%20%5C%20%5C%20%5B%5Ctext%7Bby%20z-table%7D%5D%5C%5C%5C%5C%3D0.3752)
c. The probability that a call lasts more than 4 minutes. :
F(n-1) = f(n) - 5, based off of the first one
Solve for x: x^2+4x-5=16x
first take 16x from both sides of the equation
x²-12x-5=0
now we have a quadratic. we can solve it by using the quadratic formula
x=-b plus or minus the square root of b²-4ac all divided by 2a
where a=1, b=-12 and c=-5
plug these numbers into the formula
x=12 plus or minus the square root of 144-4x1x-5 all divided by 2
<span>x=12 plus or minus the square root of 164 all divided by 2
or in decimal form </span>x = {12.403124237, -0.403124237}
100%/x%=80/20
(100/x)*x=(80/20)*x - we multiply both sides of the equation by x
100=4*x - we divide both sides of the equation by (4) to get x
100/4=x
25=x
x=25
1200 + 150 = 1350 (if one day and one use)
Budget is 3600
We can use the crane 16 times
Explanation:
Budget is 3600 and 1200 + 150 (16) = 3600
