<span> r+5 </span><span>r^2+4r-21
</span><span>-------------- / --------------------
r^2+5r-14 </span><span>r-2
</span> r+5 r-2
= -------------- x --------------------
r^2+5r-14 r^2+4r-21
r+5 r-2
= -------------- x --------------------
(r+7)(r-2) (r+7)(r-3)
r+5
= -----------------
(r+7)^2 (r-3)
Answer:
To calculate the relative frequency, first we need to know what exactly is and how to calculate it.
Relative frequency is the ratio between the absolute frequency (how many repetitions have a specific outcome) and the total outcomes. Also, this type of frequency is used to show the representation that some data have over the whole distribution.
So, in this case, we need to just divide 13, which belongs to red marble's results, to 60 which is the total outcomes, as it's presented:
13redmarble Fr = -------------------------
60 totalmarbles
Normally, relative frequency is shown as a percentage multiplying this result by 100. Therefore, 22% is the approximate percentage of the relative frequency, which means that 22% is the representation of red marbles outcomes of the whole distribution, or we can say it as a probability: there's 22% of chances when someone extract a marble, it will be red.
Answer:
And we can find this probability with the normal standard distirbution or excel and we got:
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:
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 with the normal standard distirbution or excel and we got:
104/ 8 = 13.
Every hour she vacuumed 13 cars.