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Finding the Fourth Proportional to 839.50, 1,258.95 and 319.64

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Solution

The fourth proportional to 839.50, 1,258.95 and 319.64 is: 479.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.50 : 1,258.95 = 319.64 : x
  2. Step 2: Convert to fraction form
    839.50/1,258.95 = 319.64/x
  3. Step 3: Cross multiply
    839.50x = 1,258.95 × 319.64
  4. Step 4: Simplify right side
    839.50x = 402,410.78
  5. Step 5: Solve for x
    x = 402,410.78/839.50
  6. Step 6: Final answer
    x = 479.35

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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.