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Finding the Fourth Proportional to 864.89, 1,193.35 and 491.78

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Solution

The fourth proportional to 864.89, 1,193.35 and 491.78 is: 678.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.89 : 1,193.35 = 491.78 : x
  2. Step 2: Convert to fraction form
    864.89/1,193.35 = 491.78/x
  3. Step 3: Cross multiply
    864.89x = 1,193.35 × 491.78
  4. Step 4: Simplify right side
    864.89x = 586,865.66
  5. Step 5: Solve for x
    x = 586,865.66/864.89
  6. Step 6: Final answer
    x = 678.54

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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.