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Finding the Fourth Proportional to 870.32, 1,298.73 and 778

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Solution

The fourth proportional to 870.32, 1,298.73 and 778 is: 1,160.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.32 : 1,298.73 = 778 : x
  2. Step 2: Convert to fraction form
    870.32/1,298.73 = 778/x
  3. Step 3: Cross multiply
    870.32x = 1,298.73 × 778
  4. Step 4: Simplify right side
    870.32x = 1,010,411.94
  5. Step 5: Solve for x
    x = 1,010,411.94/870.32
  6. Step 6: Final answer
    x = 1,160.97

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.