Answer:
r = 6
Step-by-step explanation:
Using Pythagoras' identity in the right triangle
PR² = PQ² + QR² , substitute values
(r + 4)² = r² + 8²
r² + 8r + 16 = r² + 64 ( subtract r² from both sides )
8r + 16 = 64 ( subtract 16 from both sides )
8r = 48 ( divide both sides by 8 )
r = 6
Answer:
A
Step-by-step explanation:
Construct a perpendicular bisector of segment AB.
Perpendicular bisector is a line that divides the line into two equal halves forming 90° at the intersection point.
So, points A and B will be at the same distance from the intersection point.
If the constructed line (perpendicular bisector) is the reflection axis, then point B will be the refection point of A.
2.443 x 10^6
Hope it helps! :)
Let Xi be the random variable representing the number of units the first worker produces in day i.
Define X = X1 + X2 + X3 + X4 + X5 as the random variable representing the number of units the
first worker produces during the entire week. It is easy to prove that X is normally distributed with mean µx = 5·75 = 375 and standard deviation σx = 20√5.
Similarly, define random variables Y1, Y2,...,Y5 representing the number of units produces by
the second worker during each of the five days and define Y = Y1 + Y2 + Y3 + Y4 + Y5. Again, Y is normally distributed with mean µy = 5·65 = 325 and standard deviation σy = 25√5. Of course, we assume that X and Y are independent. The problem asks for P(X > Y ) or in other words for P(X −Y > 0). It is a quite surprising fact that the random variable U = X−Y , the difference between X and Y , is also normally distributed with mean µU = µx−µy = 375−325 = 50 and standard deviation σU, where σ2 U = σ2 x+σ2 y = 400·5+625·5 = 1025·5 = 5125. It follows that σU = √5125. A reference to the above fact can be found online at http://mathworld.wolfram.com/NormalDifferenceDistribution.html.
Now everything reduces to finding P(U > 0) P(U > 0) = P(U −50 √5125 > − 50 √5125)≈ P(Z > −0.69843) ≈ 0.757546 .
C=2pr
r=C/(2p) and we are given C=85 so
r=85/(2p) meters
r≈13.53 meters (to nearest one-hundredth of a meter)
