**Answer:**

a = 36, b = 54

**Step-by-step explanation:**

Since the terms are in arithmetic progression then there is a common difference d between consecutive terms , that is

b - a = 72 - b ( add b to both sides )

2b - a = 72 → (1)

and

a + b - 72 = b - a ( subtract b - a from both sides )

2a - 72 = 0 ( add 72 to both sides )

2a = 72 ( divide both sides by 2 )

a = 36

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Substitute a = 36 into (1) and evaluate for b

2b - 36 = 72 ( add 36 to both sides )

2b = 108 ( divide both sides by 2 )

b = 54

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Thus a = 36 and b = 54

The sequence is therefore 36, 54, 72, 90 , .....

**Answer:**

And solving we got:

So then for the problem given the probability that the entire bath will be accepted (none is defective among the 4) is 0.583

**Step-by-step explanation:**

For this case we can model the variable of interest with the hypergeometric distribution. And with the info given we can do this:

Where N is the population size, M is the number of success states in the population, n is the number of draws, k is the number of observed successes

And for this case we want to find the probability that none of the scales selected would be defective so we want to find this:

And using the probability mass function we got:

And solving we got:

So then for the problem given the probability that the entire bath will be accepted (none is defective among the 4) is 0.583

Well if there is no number I front of a variable it is a one. For example 12c-c: 12c-1c so just take the numbers and then subtract th m and bring the c down next to the answer. 12-1:11 so 12c-1c:11c