
84% of a contractor’s jobs involves electrical work. 75% of a contractor’s jobs involve plumbing work. Of the jobs that involve plumbing, 90% of the jobs also involves electrical work. Let E = jobs involving electrical work L = jobs involving plumbing work Suppose one of the contractor’s jobs is randomly selected. Using the sixth Excel worksheet, a) Find P(E). 0.84 b) Find P(L). 0.75 c) In words, what does E | L mean? d) Find P(E | L). e) Find P(E and L). f) Are E and L independent events? Why or why not? g) Find P(E or L).
It has become somewhat fashionable to have students derive the Quadratic Formula themselves; this is done by completing the square for the generic quadratic equation ax2 + bx + c = 0. While I can understand the impulse (showing students how the Formula was invented, and thereby providing a concrete example of the usefulness of abstract symbolic manipulation), the computations involved are often a bit beyond the average student at this point.
Answer:
379/47
Step-by-step explanation:
1. Simplify
2. Reduce fraction to lowest terms
1 is the greatest common divisor of 3 and 47. The result can't be further reduced.
3. Convert mixed number to improper fraction