Answer:
since there's only 100 students how can 60 participate in sport and 50 participate in music, that must mean there is 110 students right?
T -1,-1 ect ect hope helps
Answer:
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 complement rule:

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 variable of interest 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 complement rule:

Since <em>x</em> is the number of 14-year periods, the first thing we do is divide 28 years by 14. 28/14=2. Now we use that in our function,

.

There will be 220 foxes after 28 years.
Answer: The formula for the volume of a polygon is 1/2 x perimeter x apothem