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Finding the Fourth Proportional to 690.36, 1,035.54 and 485.84

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Solution

The fourth proportional to 690.36, 1,035.54 and 485.84 is: 728.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.36 : 1,035.54 = 485.84 : x
  2. Step 2: Convert to fraction form
    690.36/1,035.54 = 485.84/x
  3. Step 3: Cross multiply
    690.36x = 1,035.54 × 485.84
  4. Step 4: Simplify right side
    690.36x = 503,109.34
  5. Step 5: Solve for x
    x = 503,109.34/690.36
  6. Step 6: Final answer
    x = 728.76

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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.