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:
He will finish the rest of the problems in 32.4 minutes.
Step-by-step explanation:
Since we are given that Yan has completed 3/5 of 45 problems i.e.


Thus he has completed 27 problems
Remaining no. of problems are 45-27 = 18
Since he complete each problem in minutes = 
So, he completes 18 problems in minutes = 18 *1.8 = 32.4 minutes
Hence , He will finish the rest of the problems in 32.4 minutes.
$45.50
2 bags = $7
13 bags=?
7÷2=3.5
3.50=1 bag
$3.50 × 13 bags = $45.50 for 13 bags of Doritos