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Finding the Fourth Proportional to 665.50, 918.40 and 403.60

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Solution

The fourth proportional to 665.50, 918.40 and 403.60 is: 556.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.50 : 918.40 = 403.60 : x
  2. Step 2: Convert to fraction form
    665.50/918.40 = 403.60/x
  3. Step 3: Cross multiply
    665.50x = 918.40 × 403.60
  4. Step 4: Simplify right side
    665.50x = 370,666.24
  5. Step 5: Solve for x
    x = 370,666.24/665.50
  6. Step 6: Final answer
    x = 556.97

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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.