The data table represents the distance between a well-known lighthouse and a cruise ship over time. The cruise ship is traveling at a uniform speed. Which equation represents the distance [tex]y[/tex] from the lighthouse, based on the number of hours [tex]x[/tex]?

\begin{tabular}{|c|c|}
\hline Number of Hours & \begin{tabular}{c}
Distance from Lighthouse \\
(in oceanic miles)
\end{tabular} \\
\hline 2 & 53 \\
\hline 4 & 95.5 \\
\hline 6 & 138 \\
\hline 8 & 180.5 \\
\hline 10 & 223 \\
\hline 12 & 265.5 \\
\hline 14 & 308 \\
\hline 16 & 350.5 \\
\hline
\end{tabular}

A. [tex]y = 42.5x + 10.5[/tex]
B. [tex]y = 10.5x + 32[/tex]
C. [tex]y = 21.25x + 10.5[/tex]
D. [tex]y = 12.25x + 28.5[/tex]
E. [tex]y = 12.5x + 10.5[/tex]



Answer :

To determine which equation represents the distance [tex]\( y \)[/tex] from the lighthouse based on the number of hours [tex]\( x \)[/tex], we can follow these steps:

1. Gather the Given Data Points:
We have the following table representing the distance from the lighthouse over time:
[tex]\[ \begin{array}{|c|c|} \hline \text{Number of Hours} & \text{Distance from Lighthouse (in oceanic miles)} \\ \hline 2 & 53 \\ \hline 4 & 95.5 \\ \hline 6 & 138 \\ \hline 8 & 180.5 \\ \hline 10 & 223 \\ \hline 12 & 265.5 \\ \hline 14 & 308 \\ \hline 16 & 350.5 \\ \hline \end{array} \][/tex]

2. Understand Linear Relationship:
Since the cruise ship is traveling at a uniform speed, the relationship between the distance [tex]\( y \)[/tex] and the time [tex]\( x \)[/tex] should be linear:
[tex]\[ y = mx + b \][/tex]
where [tex]\( m \)[/tex] is the slope (rate of speed) and [tex]\( b \)[/tex] is the y-intercept (initial distance).

3. Calculate Slope and Intercept:
First, we identify the values for [tex]\( x \)[/tex] (time in hours) and [tex]\( y \)[/tex] (distance from the lighthouse). We then use these values to determine the best-fit line.

4. Match with Given Options:
We compare the calculated slope and intercept with the given options:

[tex]\[ \begin{array}{|c|c|} \hline \text{Option} & \text{Equation} \\ \hline \text{A} & y = 42.5x + 10.5 \\ \hline \text{B} & y = 10.5x + 32 \\ \hline \text{C} & y = 21.25x + 10.5 \\ \hline \text{D} & y = 12.25x + 28.5 \\ \hline \text{E} & y = 12.5x + 10.5 \\ \hline \end{array} \][/tex]

5. Select the Correct Option:
After comparing the options with the calculated slope and intercept, the correct equation that matches the data points is:
[tex]\[ \boxed{y = 21.25x + 10.5} \][/tex]

Thus, the equation that best represents the distance from the lighthouse over time is given by option [tex]\( C \)[/tex].