hi <3
439.612, 439.261, 439.216, 439.126
hope this helps :)
<h2>
The crime gets cleaned up at 2:00 PM</h2>
Step-by-step explanation:
Let the work be w.
Batman can clean up all of the crime in Gotham City in 8 hours working alone.

Robin can do the same job alone in 12 hours.

Robin starts work at 8:00 AM and Batman Joins at 10:00 AM.
Let the time of completion of work after Batman's joining be t.
We have time of working of Robin = t + 10:00 -8:00 = t + 2
So

After 4 hours of 10:00 Am work gets completed.
Time = 10:00 AM + 4 hours = 2:00 PM
The crime gets cleaned up at 2:00 PM
Answer: 0.6812
Step-by-step explanation:
Let p be the population proportion of trees are infested by a bark beetle.
As per given: p= 12%= 0.12
Sample size : n= 1000
Number of trees affected in sample = 1000
Sample proportion of trees are infested by a bark beetle. = 
Now, the z-test statistic : 
So, 

Hence, the value of the z-test statistic = 0.6812 .