The second one t=250d because 5000 divided by 20 =250
Answer:
3/8, 6/8, 5/8
Step-by-step explanation:
that is the right answer
Answer:
1/(c - d)
Step-by-step explanation:
Multiply numerator and denominator by cd, then factor the denominator and cancel the common factor. (The result is restricted to c+d ≠ 0.)

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 .