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Finding the Fourth Proportional to 715.10, 986.85 and 400.39

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Solution

The fourth proportional to 715.10, 986.85 and 400.39 is: 552.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.10 : 986.85 = 400.39 : x
  2. Step 2: Convert to fraction form
    715.10/986.85 = 400.39/x
  3. Step 3: Cross multiply
    715.10x = 986.85 × 400.39
  4. Step 4: Simplify right side
    715.10x = 395,122.40
  5. Step 5: Solve for x
    x = 395,122.40/715.10
  6. Step 6: Final answer
    x = 552.55

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.