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3 years ago

PLS HELP! If f(x) = 3x2 – 2x – 11, what is the value of f(-3)?

Mathematics

1 answer:

natita [175]3 years ago

8 0

9514 1404 393

Answer:

Step-by-step explanation:

Put -3 where x is and do the arithmetic.

f(-3) = 3(-3)² -2(-3) -11 = 27 +6 -11

f(-3) = 22

_____

<em>Additional comment</em>

Sometimes evaluation is easier if you rewrite the polynomial in Horner form:

f(x) = (3x -2)x -11

f(-3) = (3(-3) -2)(-3) -11 = -11(-3) -11 = 33 -11 = 22

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Answer:

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Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

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If the expert is right, what is the probability that a random sample of 100 independent persons will cause an overload

Total load of more than 20,000 pounds, which is 1 subtracted by the pvalue of Z when X = 20000. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{20000 - 20000}{300}$

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