If 3 marbles are drawn from a bag of 12 marbles consisting of three red, four white and five blue, without returning them to the bag, what is the probability that the first marble is red the second is white and the third is blue?

The probability of that happening is 1/22

Step-by-step explanation:

In order to find the probability, you need to start by finding the probability for each step. The probability of the first one being red is the number of red marbles divided by the total number of marbles.

3 red / 12 total.

3/12

1/4

Now the chance that the second is white is the total number of white marbles divided by how many are left in the bag.

4 white / 11 left

4/11

Lastly, the chance of the last one being blue is the number of blue marbles divided by the amount of total marbles left after two pulls.

5 blue/ 10 left

5/10

1/2

Now to find the overall probability of all 3 happening, we multiply all 3 probabilities together.

1/4 * 4/11 * 1/2 = 1/22

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

it's d

step-by-step explanation: