<span>In 4 years, you will have $324.73</span>
Well 40 times 6 is 240 which means that you don't have to round.
Tammy's sample may not be considered valid because, on the first hand, it is said that she only asked students from her " Math Class".
If she wants to have a survey to find out the favorite subject of the students at her school, she must conduct a survey involving all the students in her school, not just in her class. What she did is just subjective. She should use a tally listing the different subjects and compare the number of students per subject. This way, she can have an objective representation of the least liked subjects and the most liked subjects of the students on her school.
Illustrating her survey through statistics may be more reliable and valid because it shows frequencies in which she can calculate easily and accurately the percentage of the number of students per subject, in a more objective manner.
<u>Answer</u>
c. buying it at a 10 percent discount without sales tax.
<u>Explanation</u>
We are going to compare the 3 choices and then determine the most cost effective.
<em>a. using a paid membership card to buy it at a 10 percent discount.</em>
10% of $100 = 10/100×100 = $10
cost = $100 - $10 = $90
On top of this $90 there is the charges of the membership card.
<em> b. buying it online at a 10 percent discount with a $5 shipping charge.</em>
100%-10% = 90%
90% of 100 = $90
Cost: $90 + $5 = $95
<em>c. buying it at a 10 percent discount without sales tax.</em>
100% - 10% = 90%
90/100 × 100 = $90. This is the must cost effective method since there is no other cost involved.