I BET NO ONE KNOWS THIS y varies jointly as x and z. y=20 when x=2 and z=5 . Find y when x=3 and z=6

Mathematics

1 answer:

Greeley [361]2 years ago

6 0

Hello!

If y varies jointly with x and z, it'll mean that x and z are being multiplied by a factor "k", to equal y.

To give you a visual, this is what I mean.

$y=kxz$

That means we'll want to find $k$ with the first point we're given: $(2,20,5)$

$20=k(2)(5)$

$20=10k$

$k=2$

Which means our equation is:

$y=2xz$

Now, let's plug in the $x$ and $z$ from the other point to find $y$ .

$y=2(3)(6)$

$y=36$

Hope this helps!

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Ket [755]

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2 years ago

A researcher is interested in the lengths of brook trout, which are known to be approximately Normally distributed with mean 80

aliya0001 [1]

Answer:

$P(X$

And we can find this probability with the normal standard distirbution or excel and we got:

$P(z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the lenghts of a population, and for this case we know the distribution for X is given by:

$X \sim N(80,5)$