Answer:
25 boys.
Step-by-step explanation:
To solve this problem, first add the two parts of the ratio. 9 + 5 = 14. Then divide 70 by 14 to get 5. Since the total is 5 times the ratio total, multiply both sides of the ratio by 5. The result is 45 : 25. If you add them together, you get a total of 70. Therefore, there are 25 boys in the class.
Answer:

And we can use the probability mas function and we got:
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:
And we want this probability:

And we can use the probability mas function and we got:
1. The range of a function is the set of all values that f can produce for all the x-es in the domain.
2. If we are given the graph, in order to find the range, we project the graph into the y axis. Informally, we draw the "shadow" of the graph into the y axis as in the FIGURE atached.
3. The range is <span>D || {y | −5 ≤ y ≤ −1}</span>