Answer:

Step-by-step explanation:
Previous concepts
The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".
Solution to the problem
Let X the random variable of interest, on this case we now that:

The probability mass function for the Binomial distribution is given as:

Where (nCx) means combinatory and it's given by this formula:

The mean for the binomial distribution is given by:

And the variance is given by:

And the deviation is just the square root of the variance so we got:

Answer:
D) 3.28
Step-by-step explanation:
820/x=100/2.5
(820/x)*x=(100/2.5)*x - we multiply both sides of the equation by x
820=40*x - we divide both sides of the equation by (40) to get x
820/40=x
20.5=x
x=20.5
now we have:
2.5% of 820=20.5
Answer: Irrational because cannot be turned into fractions
Step-by-step explanation:
Answer:
The smaller board would be 2.75 feet and the longer one would be 10.25 feet.
Step-by-step explanation:
In order to find this, assume the shorter board is equal to x. Next, we would know that the longer board would be equal to x + 7.5. Using these two assumptions, we can add the lengths together, set equal to 13 and then solve for x.
x + (x + 7.5) = 13
2x + 7.5 = 13
2x = 5.5
x = 2.75
Now that we have the length of the shorter board, we can add 7.5 to it to get the larger one.
2.75 + 7.5 = 10.25
Because the shape is a cube, we know that all sides must be 5cm. To find the area of a side, you do base × height, so 5 × 5 = 25. If you look at the net, you'll notice that there are 6 faces, which means you have to do 25 × 6 = 150cm^2. I hope this helps!