Answer:
The sample space for selecting the group to test contains <u>2,300</u> elementary events.
Step-by-step explanation:
There are a total of <em>N</em> = 25 aluminum castings.
Of these 25 aluminum castings, <em>n</em>₁ = 4 castings are defective (D) and <em>n</em>₂ = 21 are good (G).
It is provided that a quality control inspector randomly selects three of the twenty-five castings without replacement to test.
In mathematics, the procedure to select k items from n distinct items, without replacement, is known as combinations.
The formula to compute the combinations of k items from n is given by the formula:

Compute the number of samples that are possible as follows:


The sample space for selecting the group to test contains <u>2,300</u> elementary events.
Answer:
A (52,2%, 55,8%)
Step-by-step explanation:
To get the confidence interval, we have to add the margin of error to the point estimator.
The middle of the interval is 54%, and the ME is 1.8%. Don't forget that this means ±1.8%!
54 - 1.8 = 52.2%
54 + 1.8 = 55.8%
So our confidence interval is (52,2%, 55,8%) and the answer is A.
1/4+5/4=1.5
1.5 divided by 4 = 0.5625