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Finding the Fourth Proportional to 690, 1,035 and 279.44

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Solution

The fourth proportional to 690, 1,035 and 279.44 is: 419.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    690 : 1,035 = 279.44 : x
  2. Step 2: Convert to fraction form
    690/1,035 = 279.44/x
  3. Step 3: Cross multiply
    690x = 1,035 × 279.44
  4. Step 4: Simplify right side
    690x = 289,220.40
  5. Step 5: Solve for x
    x = 289,220.40/690
  6. Step 6: Final answer
    x = 419.16

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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.