Answer:
D = -6, E = -8 , F = 0
Step-by-step explanation:
standard form =
now, when circle passes through (3,-1);
⇒
⇒ ...............( equation 1)
when circle passes through (-2,4);
⇒
⇒ ...............( equation 2)
when circle passes through (6,8);
⇒
⇒ ................( equation 3)
by solving these 3 equations , we get;
D = -6, E = -8, F = 0
hence,
standard form =
=
Answer:
81.85% of the workers spend between 50 and 110 commuting to work
Step-by-step explanation:
We can assume that the distribution is Normal (or approximately Normal) because we know that it is symmetric and mound-shaped.
We call X the time spend from one worker; X has distribution N(μ = 70, σ = 20). In order to make computations, we take W, the standarization of X, whose distribution is N(0,1)
The values of the cummulative distribution function of the standard normal, which we denote , are tabulated. You can find those values in the attached file.
Using the symmetry of the Normal density function, we have that . Hece,
The probability for a worker to spend that time commuting is 0.8185. We conclude that 81.85% of the workers spend between 50 and 110 commuting to work.