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Finding the Fourth Proportional to 870.29, 1,305.58 and 431.56

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Solution

The fourth proportional to 870.29, 1,305.58 and 431.56 is: 647.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.29 : 1,305.58 = 431.56 : x
  2. Step 2: Convert to fraction form
    870.29/1,305.58 = 431.56/x
  3. Step 3: Cross multiply
    870.29x = 1,305.58 × 431.56
  4. Step 4: Simplify right side
    870.29x = 563,435.03
  5. Step 5: Solve for x
    x = 563,435.03/870.29
  6. Step 6: Final answer
    x = 647.41

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.