Help me to do this question plz plz plz I will mark you as brainlist who has answered right
1 answer:
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Answer:
And we can find this probability using the normal standard table or excel and we got:
The figure shows the calculation for this case.
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 hardness 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 normal standard table or excel and we got:
The figure shows the calculation for this case.
Answer:
The equations represent circles that result in the same graph.
Step-by-step explanation:
we have
Divide by -10 both sides
-----> equation A
This is the equation of a circle centered at origin with radius
and
Divide by 5 both sides
-----> equation B
This is the equation of a circle centered at origin with radius
equation A and equation B are equal
therefore
The system has infinite solutions, because the equations represent circles that result in the same graph.