PLEASE PLEASE PLEASE HELP I NEED IT What is the sum of the series?

Mathematics

1 answer:

JulsSmile [24]3 years ago

7 0

Formula :

$n\left(a_1+\frac{d\left(n-1\right)}{2}\right)$

Plug in the values :

$20\left(1+\frac{-3\left(20-1\right)}{2}\right) = 550$

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Answer:550
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A company interested in lumbering rights for a certain tract of slash pine trees is told that the mean diameter of these trees i

brilliants [131]

Answer:

97.6% of the trees will have diameters between 7.6 and 18.6 inches.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 12 inches

Standard Deviation, σ = 2.2 inches

We are given that the distribution of diameter of tree is a mound shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

P(diameters between 7.6 and 18.6 inches)

$P(7.6 \leq x \leq 18.6) = P(\displaystyle\frac{7.6 - 12}{2.2} \leq z \leq \displaystyle\frac{18.6-12}{2.2}) = P(-2 \leq z \leq 3)\\\\= P(z \leq 3) - P(z < -2)\\= 0.999 - 0.023 = 0.976= 97.6\%$