Answer:
The volume of the ball with the drilled hole is:

Step-by-step explanation:
See attached a sketch of the region that is revolved about the y-axis to produce the upper half of the ball. Notice the function y is the equation of a circle centered at the origin with radius 15:

Then we set the integral for the volume by using shell method:

That can be solved by substitution:

The limits of integration also change:
For x=5: 
For x=15: 
So the integral becomes:

If we flip the limits we also get rid of the minus in front, and writing the root as an exponent we get:

Then applying the basic rule we get:

Since that is just half of the solid, we multiply by 2 to get the complete volume:


Answer:

And replacing we got:

And then the estimator for the standard error is given by:

Step-by-step explanation:
For this case we have the following dataset given:
20.05, 20.56, 20.72, and 20.43
We can assume that the distribution for the sample mean is given by:

And the standard error for this case would be:

And we can estimate the deviation with the sample deviation:

And replacing we got:

And then the estimator for the standard error is given by:

Answer:
0.12=zero point one two
Step-by-step explanation:
Answer:
2/45
Step-by-step explanation:
We are told that:
A jar contains 2 orange, 4 green, 2 white and 2 black balls.
The total number of balls in the jar is calculated as:
2 orange balls + 4 green balls + 2 white balls + 2 black balls = 10 balls
The probability of drawing an orange ball = P(Orange) = 2/10
The probability of drawing a black ball = P(Black) = 2/10
Therefore, the probability of drawing an orange ball without putting it back, then drawing a black ball is calculated as:
2/10 × 2/9 = 4/90
= 2/45