Answer:
Falso
Step-by-step explanation:
Answer:
0.7698
Step-by-step explanation:
If you call your random variable
, then what you are looking for is

because you want the probability of
being <em>between 87 and 123.</em>
We need a table with of the normal distribution. But we can only find the table with
and
. Because of that, first we need to <em>normalize </em>our random variable:

(you can always normalize your variable following the same formula!)
now we can do something similar to our limits, to get a better expression:


And we transform our problem to a simpler one:
(see Figure 1)
From our table we can see that
(this is represented in figure 2).
Remember that the whole area below the curve is exactly 1. So we can conclude that
(because 0.8849 + 0.1151 = 1). We also know the normal distribution is symmetric, then
.
FINALLY:

Answer:
x = - 7
Step-by-step explanation:
Given
- 2(x + 5) = 4 ← distribute the parenthesis by - 2
- 2x - 10 = 4 ( add 10 to both sides )
- 2x = 14 ( divide both sides by - 2 )
x = - 7
Max amount of people who can attend is 10.
200-160=40
40 ÷4= 10