Statistics and Probability Answers

1. How many different 3-digit odd numbers can be formed with the digits 0, 1, 2 up to 9 if repetition of digits is not allowed?

suppose a room has two doors. In how many ways can one enter and leave the room?

how many three digit numbers can be formed from the set 0,1,2,...,9 if repetitions are not allowed and the number must be divisible by a)10 b)25.

If the statistical odds of getting a disease across the general population stands at 8/100,000. What are the chances against 3 people in a workforce of 130 contracting it?

For a Normal distribution with mean, μ=2, and standard deviation, σ=4, 30% of all observations have a value less than

For a Normal distribution with mean, μ=2, and standard deviation, σ=4, 40% of all observations have a value greater than

For a normal distribution with mean, μ=2, and standard deviation, σ=4 what proportion of observations take values less than 1?

Can you also please explain how to get the answer?

if the papers of 4 students can be checked by any of the 7 teachers,the show that the probability that all the 4 papers are checked by exactly 2 teachers is 6/49

Is the following a mutually exclusive or inclusive event. The probability of drawing a card at random and it is a queen or a diamond.

"a box contain 500 envelops for prizes of different categories of which 75 contains 500php in cash, 150 contain 250php and 275 contain 100php. an envelope may be purchased for 250php. what is the sample space for the different mount of money? assign probability to sample points and then find the probability that the first envelope purchased contains less than 500php. With solution".

Which is NOT a step in calculating the standard deviation?
Square each individual difference
Square each of the X values and compute the sum of all the Y values
Sum all of the squared deviations about the mean
Divide the sum by n - 1

The odds in favor of a family with 3 children having all girls are 1to 7
what is the probability of this event occuring?
if 100 three children families surveyed how many of these would most likely have girls