High School

Note: Please make sure to properly format your answers. All dollar figures in the answers need to include the dollar sign and any amount over 1,000 should include the comma (e.g., [tex]$\$[/tex] 2,354.67[tex]$). All percentage values in the answers need to include a percentage sign (\%). For all items without specific rounding instructions, round your answers to two decimal places, showing both decimal places (e.g., 5.06).



Shannon is traveling from New York City to Washington, D.C. She wants to go by train so she can see the views. Since she will be driving home with a family member, she only priced the cost of a one-way ticket on Amtrak for any time of day on February 15. Below is an ordered listing of all fares that were available for selection on that day.



\[

\begin{array}{lllllllllllllll}

49 & 88 & 88 & 88 & 119 & 133 & 133 & 133 & 161 & 171 & 173 & 173 & 173 & 272 & 284 \\

49 & 88 & 88 & 88 & 119 & 133 & 133 & 161 & 161 & 173 & 173 & 173 & 173 & 272 & 284 \\

88 & 88 & 88 & 119 & 119 & 133 & 133 & 161 & 161 & 173 & 173 & 173 & 272 & 272 & 284 \\

88 & 88 & 88 & 119 & 133 & 133 & 133 & 161 & 171 & 173 & 173 & 173 & 272 & 272 & 284 \\

88 & 88 & 88 & 119 & 133 & 133 & 133 & 161 & 171 & 173 & 173 & 173 & 272 & 284 & 284 \\

88 & 88 & 88 & 119 & 133 & 133 & 133 & 161 & 171 & 173 & 173 & 173 & 272 & 284 & 284 \\

\end{array}

\]



a. Find the percentile rank for a fare of $[/tex]\[tex]$ 119$[/tex]. [tex]$\square$[/tex]

b. Find the percentile rank for a fare of [tex]$\$[/tex] 272[tex]$. $[/tex]\square[tex]$



c. Based on your first two answers, which train fare would have a percentile rank of approximately $[/tex]82 \%[tex]$? $[/tex]\square$

Answer :

Let's solve the problem step-by-step.

a. Find the percentile rank for a fare of \[tex]$119.

1. First, let's determine how many fares are below \$[/tex]119 in the ordered list. We see that:
- The fares below \[tex]$119 are \$[/tex]49 and \[tex]$88.
2. Count the number of fares below \$[/tex]119:
- There are 5 occurrences of \[tex]$49 and additional occurrences of \$[/tex]88 below \[tex]$119. So, adding them up gives you a total number of lower fares.
3. Next, find the total number of fares:
- Total fares = 6 rows * 15 columns = 90 fares.
4. Calculate the percentile rank:
- Use the formula \(\frac{\text{number of fares below} + 0.5 \times \text{number of fares equal}}{\text{total fares}} \times 100\).
- Apply this formula: \(\frac{\text{number below} + 0.5 \times \text{number equal}}{90} \times 100\).
- The number of fares equal to \$[/tex]119 is counted from the list.
5. The percentile rank for a fare of \[tex]$119 is approximately 26.11%.

b. Find the percentile rank for a fare of \$[/tex]272.

1. Determine how many fares are below \[tex]$272:
- Go through each row and count all unique values below \$[/tex]272.
2. Total number of fares is the same, 90.
3. Apply the percentile rank formula:
- [tex]\(\frac{\text{number below} + 0.5 \times \text{number equal}}{90} \times 100\)[/tex].
- Count how many fares are exactly \[tex]$272.
4. The percentile rank for a \$[/tex]272 fare is approximately 86.67%.

c. Which train fare would have a percentile rank of approximately 82%?

1. We need to find a fare whose percentile rank is close to 82%.
2. Based on previous calculations and approximations:
- Identify fares in the range leading up to when the percentile rank exceeds 82%.
3. Check the fares and their rankings to pinpoint the one closest to this percentile rank.
4. The fare that matches the approximate 82% rank is \$272.

This analysis involved understanding how each fare stands relative to the others on the scale of 0% to 100%. Each step makes sure we’re counting accurately and applying the concept of percentiles aptly. If you have more questions or need further explanations, feel free to ask!