Question

think back to how boat anchors are damaging corals on seafoam island. read the passage below about the island. then use the table to answer the question.
the residents wanted to know whether the damage to corals could allow seaweed to take over the reef.
so, scientists from seafoam island began a study to find out how much of the reef was covered in seaweed instead of corals. the scientists collected data from the reef by using transects. a transect is a line of measuring tape that is laid across the surface of a reef. scientists can record how much of the line is over seaweed and how much is over corals.
data from transects can be used to estimate how much of a reef is covered in seaweed, using the following equation:
percentage of reef covered in seaweed = \\( \frac { \text { length of transect covered in seaweed } } { \text { total length of transect } } \times 100 \\)
to see how the reef changed over time, the seafoam island scientists collected data from many transects over several years. the table below shows data that scientists collected from four transects during the study of seafoam reef. year 0 is the year that the scientists began the study.
each transect had a total length of 20.0 meters. use this information to complete the table.

Explanation:

Step1: Calculate for Year 0

Use the formula \( \text{percentage}=\frac{\text{length of transect covered in seaweed}}{\text{total length of transect}}\times100\).
For Year 0, length of transect covered in seaweed \(l = 0.80\) m and total length \(L=20.0\) m.
\(\text{percentage}=\frac{0.80}{20.0}\times 100\)
\(=\frac{0.80\times100}{20.0}\)
\( = 4.0\%\)

Step2: Calculate for Year 2

Length of transect covered in seaweed \(l = 1.50\) m and total length \(L = 20.0\) m.
\(\text{percentage}=\frac{1.50}{20.0}\times100\)
\(=\frac{1.50\times100}{20.0}\)
\(=\frac{150}{20.0}=7.5\%\)

Step3: Calculate for Year 3

Length of transect covered in seaweed \(l = 2.04\) m and total length \(L=20.0\) m.
\(\text{percentage}=\frac{2.04}{20.0}\times100\)
\(=\frac{2.04\times100}{20.0}\)
\(=\frac{204}{20.0}=10.2\%\)

Answer:

Year 0: \(4.0\%\), Year 2: \(7.5\%\), Year 3: \(10.2\%\)