Answer:
And we can find this probability using the complement rule:
And using the normal standard distirbution table or excel 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 variable if interest of a population, and for this case we know the distribution for X is given by:
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:
And using the normal standard distirbution table or excel we got:
Step-by-step explanation:
Is this the full question
Answer: 
Step-by-step explanation:
Move all terms to one side
Simplify
Split the second term
Factor out common terms in the first two terms, then in the last two terms.
Factor out the common term

Answer:
Sirius will be 20 years old and his father will be 40 years old. ratio form: 20:40
Step-by-step explanation:
hope this helps
Answer:
80
Step-by-step explanation:
Look at the box plot and look at each line.
The first line that is all the way to the left, that is the Quartile 1.
The last line all the way to the right, that is Quartile 3.
Now lets look at the box part.
The beggining of the box is the minimum.
The ending of the box is the maximum.
The middle line is the median.
How I remember it is Median=Middle
Hopw this hels :D