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Finding the Fourth Proportional to 690.48, 1,036.75 and 678.18

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Solution

The fourth proportional to 690.48, 1,036.75 and 678.18 is: 1,018.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.48 : 1,036.75 = 678.18 : x
  2. Step 2: Convert to fraction form
    690.48/1,036.75 = 678.18/x
  3. Step 3: Cross multiply
    690.48x = 1,036.75 × 678.18
  4. Step 4: Simplify right side
    690.48x = 703,107.85
  5. Step 5: Solve for x
    x = 703,107.85/690.48
  6. Step 6: Final answer
    x = 1,018.28

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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.