Using the geometric mean concept, it is found that the value of a is 18.
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The geometric mean, of a data-set of n elements, , is given by:
That is, the nth root of the multiplication of all elements.
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In this question:
Thus:
We find the square of each side, so:
Simplifying both sides by 17:
The value of a is 18.
A similar example is given at brainly.com/question/15010240
Answer:
Step-by-step explanation:
This is a Combination (as in permutation vs combination) question the symbol (n r) refers to "n choose r". This is sometimes written as nCr
i.e the question is asking you to find how many combinations each will yield when you chose r items from n item without repetition and order does not matter.
I will only do the first question for you and you can just follow the same steps to solve the rest of the questions.
Recall that
Consider question a) we are given (5 1) or ₅C₁
we can see that n = 5 and r = 1
If we substitute this into the formula:
₅C₁ = (5!) / [ (1!)(5- 1)!]
= (5!) / [ (5- 1)!]
= (5!) / (4!)
= (5·4·3·2·1) / (4·3·2·1)
= 5
hence ₅C₁ = 5
