Answer:
The probability is 0.503
Step-by-step explanation:
If the ghost appearances occur in the house according to a Poisson process with mean m, the time between appearances follows a exponential distribution with mean 1/m. so, the probability that the next ghost appearance happens before x hours is equal to:

Then, replacing m by 1.4 ghosts per hour we get:

Additionally, The exponential distribution have a memoryless property, so if it is now 1:00 p.m. and we want the probability that ghost appear before 1:30 p.m., we need to find the difference in hours from 1:00 p.m and 1:30 p.m. no matter that the last ghost appearance was at 12:35 p.m.
Therefore, there are 0.5 hours between 1:00 p.m. and 1:30 p.m, so the probability that the 7th ghost will appear before 1:30 p.m is calculated as:

Answer:
a = 3
b = 4
c = 5
Step-by-step explanation:
This is a rhombus. A property of a rhombus is that their diagonals perpendicularly bisect each other. In other words, if the point in the center is A, then HA = MA and EA = OA. So: 3 = a and 4 = b.
Since angle HAO forms a right angle, we can use the Pythagorean Theorem to say that HA^2 + AO^2 = OH^2: 3^2 + 4^2 = 9 + 16 = 25.
OH^2 = 25
OH = 5
Hope this helps!