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Finding the Fourth Proportional to 938.51, 1,407.39 and 390.32

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Solution

The fourth proportional to 938.51, 1,407.39 and 390.32 is: 585.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.51 : 1,407.39 = 390.32 : x
  2. Step 2: Convert to fraction form
    938.51/1,407.39 = 390.32/x
  3. Step 3: Cross multiply
    938.51x = 1,407.39 × 390.32
  4. Step 4: Simplify right side
    938.51x = 549,332.46
  5. Step 5: Solve for x
    x = 549,332.46/938.51
  6. Step 6: Final answer
    x = 585.32

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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.