Answer:
5
Step-by-step explanation:
The radius is 5.
All I do was think of the center-radius form a circle
(x-h)^2+(y-k)^2=r^2
x^2 + y^2 =25
(x-0)^2+(y-0)^2=5^2
The center is (0,0) and the radius is 5.
So a point on the circle (x,y) has a distance of 5 from the center
and the center's case here is (0,0).
C is the answer hope this helps.
Answer:


And using a calculator, excel ir the normal standard table we have that:

And we can calculate the probability like this:
Step-by-step explanation:
A random sample of 36 observations has been drawn from a normal distribution with mean 50 and standard deviation 12. Find the probability that the sample mean is in the interval 47<=X<53. Is the assumption of normality important. Why?
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 of interest of a population, and for this case we know the distribution for X is given by:
Where
and 
Since the distribution for X is normal then we know that the distribution for the sample mean
is given by:

We can find the probability required like this:


And using a calculator, excel ir the normal standard table we have that:

And we can calculate the probability like this:

Answer:
- 14, - 7 or 7, 14
Step-by-step explanation:
Let the the two integers be x and (x + 7)

Hence the required integers are - 14, - 7 or 7, 14
Answer:
x > 3
Step-by-step explanation:
Step 1: Isolate x
6x -6 > 12
6x > 18
Step 2: Divide
x > 3