Answer:
78.88%
Step-by-step explanation:
We have been given that

The z-score formula is given by

For 

For 

Now, we find the corresponding probability from the standard z score table.
For the z score -1.25, we have the probability 0.1056
For the z score 1.25, we have the probability 0.8944
Therefore, the percent of the trees that are between 20 and 30 years old is given by
0.8944 - 0.1056
= 0.7888
=78.88%
Answer : 
Explanation:
Since we have given that
n(U) = 120, where U denotes universal set ,
n(F) = 45, where F denotes who speak French,
n(S) = 42 , where S denotes who speak Spanish,
n(F∪S)' = 50
n(F∪S) = n(U)-n(F∪S) = 120-50 = 70
Now, we know the formula, i.e.
n(F∪s) = n(F)+n(S)-n(F∩S)
⇒ 70 = 45+42-n(F∩S)
⇒ 70 = 87- n(F∩S)
⇒ 70-87 = -n(F∩S)
⇒ -17 = -n( F∩S)
⇒ 17 = n(F∩S)

Answer: 4 pizzas
Step-by-step explanation:
There are to be 12 people at the party.
Each person is expected to take 1/3 of a pizza.
The total number of pizza needed is therefore:
= No. of people * quantity of pizza
= 12 * 1/3
= 4 pizzas
<em>Note: Answer would be 6 if each guest wanted 1/2 of a pizza. </em>
Answer:
It would be 5.5
for a better understanding, look it up on google
Answer:
5/8
Step-by-step explanation:
12+30+20+10 +8 =80 total marbles
12+30+8=50 red blue and black
50/80
5/8