<span>10!/(10-6)!
=
3628800/24
=
151200
</span> So the answer is 151200
One-third is one out of three pieces of a whole.
I hope this helps, please Brainliest me, and have a great day! :D
Answer:
Step-by-step explanation:
You just need the distance formula here. It's very simple to follow:

which, for us, looks like this:
and
and
and
so
d = 15
10x + 19.95 = 139.95
Subtract 19.95 from both sides
10x =130.00
Divide both sides by 10
X = 13
13 classes
Answer:

And we can find this probability using the normal standard table or excel and we got:

The figure shows the calculation for this case.
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 hardness of a population, and for this case we know the distribution for X is given by:
Where
and 
We are interested on this probability

And the best way to solve this problem is using the normal standard distribution and the z score given by:

If we apply this formula to our probability we got this:

And we can find this probability using the normal standard table or excel and we got:

The figure shows the calculation for this case.