Let's analyze the given data regarding the contraction rates of paramecium contractile vacuoles at different salt concentrations:
- Very high concentration: 2 contractions per minute
- High concentration: 8 contractions per minute
- Medium concentration: 15 contractions per minute
- Low concentration: 22 contractions per minute
- Very low concentration: 30 contractions per minute
We are asked to verify statements about the heights of the bars on a bar graph for these contraction rates.
1. The graph has five bars of equal height.
This statement is not correct. The given rates are all different (2, 8, 15, 22, and 30), so the bars would have different heights.
2. The bars range from tallest for very high concentration to shortest for very low concentration.
This statement is also incorrect because the actual rates increase from very high concentration (2) to very low concentration (30). Thus, the bar for very high concentration would be the shortest, not the tallest.
3. The bar for very low concentration is twice the height of the bar for medium concentration.
Let's examine this claim:
- Very low concentration: 30 contractions per minute
- Medium concentration: 15 contractions per minute
To check if the bar for very low concentration is twice the height of the bar for medium concentration:
[tex]\[
\frac{\text{Very low concentration}}{\text{Medium concentration}} = \frac{30}{15} = 2
\][/tex]
Since 30 is indeed twice of 15, this statement is true.
4. The bar for very high concentration is five times the height of the bar for very low concentration.
Let's examine this claim:
- Very high concentration: 2 contractions per minute
- Very low concentration: 30 contractions per minute
To check if the bar for very high concentration is five times the height of the bar for very low concentration:
[tex]\[
\frac{\text{Very low concentration}}{\text{Very high concentration}} = \frac{30}{2} = 15
\][/tex]
Since 30 is 15 times larger than 2, and not 5 times, this statement is false.
Thus, the correct statement is:
The bar for very low concentration is twice the height of the bar for medium concentration.
