Answer:
The probability is 0.0775
The expected value is 4.75 clubs
The standard deviation is 1.8875 clubs
Step-by-step explanation:
The variable X follows a binomial distribution, because we have n identical and independent events (19 cards) with a probability p of success and 1-p of fail (there is a probability of 1/4 to be club and 3/4 to be diamond, heart or spade). Then, the probability that x of the n cards are club is:

So, the probability P of drawing at least 8 clubs is:
P = P(8) + P(9) + P(10) + ... + P(18) + P(19)
Replacing, the values of x, from 8 to 19, on the equation above, we get:
P = 0.0775
Additionally, the expected value E(x) and standard deviationS(x) for this distribution is given by:
E(x)=np = 19(0.25) = 4.75

3x-y=6, in order to be able to graph this you would have to change the equation to y=, so you need to subtract 3x from that side making it -y=-3x+6, now you need to y positive, so divide both sides by -1, thus making the equation look like y=3x-6, now if you can't plug this into a calculator to see what it would look like then you need to know what y=mx+b means. y is the equation you want to graph obviously, m = the slope, so our slope in this case would be -3, and b = our y intercept, so it would be (0,-6), so plot (0,-6) and use the slope to plot the rest of the points, some other points in this line should include (2,0), (-1,-9) and (4,6), just to name a few. Hope this helps.
the value of x is 8 cm.
<u>Step-by-step explanation:</u>
Correct Question : In the diagram, the radius of the outer circle is 2x cm and the radius of the inside circle is 6 cm. The area of the shaded region is 220π cm2. What is the value of x? Enter your answer in the box.
We have ,
the area of a circle = πr²
the outer circle area = 
the inside circle area = 
According to Question,
the outer circle area - the inside circle area = he shaded region
⇒ 
⇒ 
⇒ 
⇒
Therefore , the value of x is 8 cm.
Answer:
B or D
Step-by-step explanation: