Answer:
x = 2
Step-by-step explanation:
Since this is a 45-45-90 triangle, the 2 legs will be the same, meaning that y will also be .
We can then solve for x using the Pythagorean theorem:
Or, we could use a quicker approach: if the triangle is a 45-45-90 triangle, the hypotenuse will be times the length of 1 leg. It essentially does the same thing; it's just faster so you could save time on tests.
Answer:
a)
b)
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".
Let X the random variable that represent the mean life span of a brand name tire, and for this case we know the distribution for X is given by:
Part a
We want this probability:
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:
Part b
Let represent the sample mean, the distribution for the sample mean is given by:
On this case
We want this probability:
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: