Answer:
15.5t=18(t-0.5) is the correct answer
Step-by-step explanation:
if the first boat travels t time then the second traveld t-0.5 time to take over
Answer:
x> or equal to 35. 36 is a solution.
Step-by-step explanation:
The sample size should be 250.
Our margin of error is 4%, or 0.04. We use the formula

To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide both sides by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value has a z-score of approximately 2.33. Using this, our margin of error and our proportion, we have:

Divide both sides by 2.33:

Square both sides:

Multiply both sides by n:

Divide both sides to isolate n:
X=7%
y=12%
x+y=20000
0.07x+0.12y=20000*0.19=3800
The correct answer is B)4