Question

christopher collected a dozen leaves from each of three oak trees. he measured each leaf from the stem to the opposite tip. part of his lab book is shown below.

christopher wants to compare the data he collected, but he made an error while recording the measurements. what did christopher do wrong?

a. christopher did not record leaf size data for enough trees.
b. christopher did not report the size of each leaf in units of length.
c. christopher recorded part of his data in si units and part of it in english units.
d. christopher did not organize his data so that the leaf sizes are listed for each tree.

Explanation:

Analyze the data table

We examine the units used for the measurements of the leaves from each tree:

• Tree 1 measurements are recorded in centimeters (\(\text{cm}\)).
• Tree 2 measurements are recorded in centimeters (\(\text{cm}\)).
• Tree 3 measurements are recorded in inches (\(\text{in}\)).

Identify the error

Using the Laboratory Safety and experimental design principles, scientific data must be recorded using consistent units to allow for direct comparison.

• Centimeters (\(\text{cm}\)) belong to the International System of Units (SI units).
• Inches (\(\text{in}\)) belong to the English (Imperial) system of units.
• Christopher recorded part of his data in SI units and part of it in English units, making direct comparison difficult without conversion.

Evaluate the options

• A is incorrect because collecting data from three trees is a reasonable sample size for this simple comparison.
• B is incorrect because both centimeters and inches are units of length.
• C is correct because Tree 1 and Tree 2 are in centimeters (SI), while Tree 3 is in inches (English).
• D is incorrect because the data is clearly organized in columns for each tree.

Answer:

• A. Christopher did not record leaf size data for enough trees.
• B. Christopher did not report the size of each leaf in units of length.
• C. Christopher recorded part of his data in SI units and part of it in English units. (Correct answer)
• D. Christopher did not organize his data so that the leaf sizes are listed for each tree.