Answer:
Systematic sampling
Step-by-step explanation:
An EPA contractor needing to test the concentration of a substance in ten samples out seventy samples provided form a single source at regular time intervals.
For the contractor to effectively carry out the testing he has to employ a Non-probability system of sampling which is called Systematic sampling, because in systematic sampling we can assume the population size (x ) which in this case is 70 and the sample size( n ) to be 10
He will have to select ; ( x / n )^th of the sampling frame for best results
Answer:
C
Step-by-step explanation:
Calculate the values of both r and s, that is
= 7 ( multiply both sides by 2 )
5 + r = 14 ( subtract 5 from both sides )
r = 9
and
= 3 ( multiply both sides by 2 )
3 + s = 6 ( subtract 3 from both sides )
s = 3
Hence
= 
= 6 → C
Answer: 33 mph
Step-by-step explanation:
First find out what 40% of 55 is:
= 40% * 55
= 22 mph
This means that the speed reduces by 22 mph inside the city.
The speed inside the city is therefore:
= 55 - 22
= 33 mph
Answer:
Answer number c (0.3 liters per hour is the average rate)
Step-by-step explanation:
