Answer:
(D) This is a stratified random sample because a separate random sample is selected from each class
Step-by-step explanation:
A sample of size n is defined to be a stratified random sample if it is selected from a population which has been divided into a number of non overlapping groups or sub populations called strata, such that part of the sample is drawn at random from each stratum.
It is to be emphasized that good stratification requires that each of these strata should be internally homogeneous but externally should differ from one another.
The advantage of stratified sampling is low cost , greater accuracy and better coverage.
If we analyze the given scenario a sample is selected from each strata depicting its corresponding percentage in the population. It is internally homogeneous but externally different.
The square root of a number is a value that, when multiplied by itself, gives the number. Example: 4 × 4 = 16, so a square root of 16 is 4. But note that (−4) × (−4) = 16 also, so −4 is also a square root of 16. This is why each nonzero interger has two square roots.
The cube root of a number is a special value that, when used in a multiplication three times, gives that number. Example: 3 × 3 × 3 = 27, so the cube root of 27 is 3. But cube root is unlike square root where as -3 × -3 × -3 = -27 not 27 therefore there is only one cube root.
I hope this helps
Total purchased w/o tax: $8 +$5 + $15 = $28
He paid (w/tax) $29.82 so
$ 29.82 - $28 = $1.82 (sale tax)
Now we need to find the sales tax rate:
$1.82 / $28 * 100 = 0.065 *100% = 6.5%
Double check:
$28 *6.5 / 100 = $1.82
$28 + $ 1.82 = $29.82 total amount he paid..
So the sales tax rate is 6.5%
18b - 24c because you multiply the outside with everything inside
