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Finding the Fourth Proportional to 528.40, 728.40 and 518.68

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Solution

The fourth proportional to 528.40, 728.40 and 518.68 is: 715.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.40 : 728.40 = 518.68 : x
  2. Step 2: Convert to fraction form
    528.40/728.40 = 518.68/x
  3. Step 3: Cross multiply
    528.40x = 728.40 × 518.68
  4. Step 4: Simplify right side
    528.40x = 377,806.51
  5. Step 5: Solve for x
    x = 377,806.51/528.40
  6. Step 6: Final answer
    x = 715.00

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.