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
Sec∅ = 1/cos∅
= 1/cos(240)
= 1/cos(180 + 60)
= 1/-cos(60)
= 1/(-1/2)
= -2
The <em>correct answer</em> is:
He paid the correct amount.
Explanation:
First we find the subtotal of Manny's items:
32.65+3(14.89)+39.99 = 32.65+44.67+39.99 = 117.31
Next, we calculate the discount. If he gets 10% off, this means he pays 100%-10% = 90% of the total. 90% = 90/100 = 0.9:
0.9(117.31) = 105.579
Next we calculate the tax. Since tax is 8%, this means he pays 100% of his subtotal after discount plus the 8% tax; 100%+8% = 108%; 108% = 108/100 = 1.08:
1.08(105.579) = 114.02532 ≈ 114.03
Since this is what he paid, he paid the correct amount.
