Answer:
35/79
Step-by-step explanation:
Assuming you can't choose the same song a second time, the probability is 35/79.
If you can choose the same song, the probability is 36/80, which reduces to 9/20.
Answer:
And if we solve for a 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 hourly rates of a population, and for this case we know the distribution for X is given by:
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
Both conditions are equivalent on this case. We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.80 of the area on the left and 0.20 of the area on the right it's z=0.842. On this case P(Z<0.842)=0.8 and P(z>0.842)=0.20
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
Answer:
k = -4 or 2
Step-by-step explanation:
For the lines to be parallel, the lines would need to be the same slope. This means to find the slope of each we would take the difference of the rise over the run.

and

To find K, set them equal.

Factor the quadratic and solve for K.

k+4=0 so k=-4
k-2=0 so k=2
Answer:
See below:
Step-by-step explanation:
Hello! We can check to see if the inequality is true by replacing r with 18 as we have been told to find them in which 18 as r makes the equation true.
So our equations to test for are:

We can input 18 as r and then we see the following are correct:
1. No, as a -21 is not greater than -6
2. Yes, as -15 is less than 6.
3. No, as 21 is not greater than 6
4. No, as -15 is not greater than 6.
Cheers!