To determine the effect of adding vitamins to the diet of young rats on their weight gain, we need to analyze the weight differences and average weight gain for both groups—rats fed a normal diet and rats fed a diet with vitamins. Let's go through this step-by-step using the provided data.
Step 1: Record the weight differences for each group:
For rats fed a normal diet:
- Rat 1: Starting weight = 256 g, Ending weight = 320 g, Difference = 320 g - 256 g = 64 g
- Rat 2: Starting weight = 274 g, Ending weight = 347 g, Difference = 347 g - 274 g = 73 g
- Rat 3: Starting weight = 209 g, Ending weight = 268 g, Difference = 268 g - 209 g = 59 g
For rats fed a diet with vitamins:
- Rat 1: Starting weight = 249 g, Ending weight = 342 g, Difference = 342 g - 249 g = 93 g
- Rat 2: Starting weight = 221 g, Ending weight = 307 g, Difference = 307 g - 221 g = 86 g
- Rat 3: Starting weight = 278 g, Ending weight = 381 g, Difference = 381 g - 278 g = 103 g
Step 2: Calculate the average weight gain for each group:
For rats fed a normal diet:
- Total weight gain = 64 g + 73 g + 59 g = 196 g
- Number of rats = 3
- Average weight gain = Total weight gain / Number of rats = 196 g / 3 ≈ 65.33 g
For rats fed a diet with vitamins:
- Total weight gain = 93 g + 86 g + 103 g = 282 g
- Number of rats = 3
- Average weight gain = Total weight gain / Number of rats = 282 g / 3 = 94 g
Step 3: Compare the results and draw a conclusion:
- The average weight gain for rats fed a normal diet was approximately 65.33 g.
- The average weight gain for rats fed a diet with vitamins was 94 g.
Conclusion:
According to the data, the rats that were fed vitamins gained more weight on average (94 g) than those that were fed a normal diet (65.33 g). Thus, the scientist's hypothesis is supported by the data. The hypothesis predicted that young rats fed vitamins would gain more weight than those on a normal diet, and this prediction was confirmed by the experimental results.
