Question 1:
A factory produces on average 10 defective products a day.
- What’s the probability, in a certain day a max of 4 defective products will be generated?
- What’s the probability, in 2 days 12 to 15 defective products will be produced?
Question 2:
A regular die is tossed 6 times.
What’s the expected values of the sum of all those tosses.
Question 3:
The survival time of bulbs is normally distributed with a mean of 1200 hours and a standard deviation of 350 hours.
- What’s the chance a bulb will be able to function between 1100 and 1500 hours?
- If a bulb survived 1400 hours at least, what’s the chance it’ll last for 1550 hours?
Answer 1:
We’d assume a Poisson distribution with lambda=10.
- That’s the probability for 4 days at most:

- The accurate lambda for 2 days is 20, and thus, that’s the requested probability:

Answer 2:
The expected value of a regular die is calculated as follows:

Since the expected value of the sum, is the sum of expected values, if the die is tossed 6 times, the overall expected value will be 6*3.5=21
Answer 3:
The survival time of the bulbs is normally distributed like this: X~N(mu=1200, sd=350).
The relevant calculation is this:
- The relevant calculation is this:

- That’s the relevant calculation in that case:
