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3 years ago

What will be the first negative term in the sequence 87,84,81

Mathematics

1 answer:

o-na [289]3 years ago

8 0

Answer:

a₃₁

Step-by-step explanation:

The terms have a common difference between consecutive terms, that is

d = 84 - 87 = 81 - 84 = - 3

This indicates the sequence is arithmetic with nth term

$a_{n}$ = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 87 and d = - 3 , then

$a_{n}$ = 87 - 3(n - 1) = 87 - 3n + 3 = 90 - 3n

To find when $a_{n}$ < 0 , solve

90 - 3n < 0 ( subtract 90 from both sides )

- 3n < - 90

Divide both sides by - 3, reversing the symbol as a result of dividing by a negative quantity, then

n > 30

Thus the 31st term will be the first negative term

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Answer:

$\= x = 18.5$ , $\sigma = 5.15$

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Step-by-step explanation:

From the question we are are told that

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The 95% confidence interval is evaluated as

$\= x - E < \mu < \= x + E$

substituting values

$18.5 - 3.569 < \mu < 18.5 + 3.569$

$14.93 < \mu < 22.069$

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What will be the first negative term in the sequence 87,84,81​

What will be the first negative term in the sequence 87,84,81