The exponential distribution is:

where

The probability we want is how likely will a dvd player last more than 8 years, given it has already lasted 5 years
To find this, you use conditional probability.

where A is P(x>8) and B is P(x>5)
To find these probabilities, integrate over the distribution:

Sub into conditional probability formula:

Final Answer: Given a dvd player is more than 5 years old, the probability that it will last another 3 more years is about 54.9%
Answer:
B) 3.2 mi
Step-by-step explanation:
1. The midpoints: midpoint formula = <em>((x₁ + x₂)/2, (y₁+ y₂)/2)</em>
upper = ((6 + -4)/2, (8 + 0)/2) --><em> (1, 4)</em>
lower = ((-8 + 2)/2, (3 + -5)/2) --><em> (-3, -1)</em>
2. Distance: distance formula = <em>√((x₁ - x₂)² + (y₁ - y₂)²)</em>
√((1 + 3)² + (4 + 1)²) = √(16 + 25) = √41 ≈ 6.403... ≈ <em>6.4</em>
3. Scale: 6.4 * 0.5 mi = 3.2 mi
46 and 19. 46 x 19 = 874 and 46 - 19 = 27
Any irrational number, for example the square root of 2 or pi.
We will assume that the number is n
one eighth of the number = 1/8 x n = n/8
we know that this result n/8) is less than or equal (<=) 3
therefore, the inequality is:
n/8 <= 3