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Finding the Fourth Proportional to 852.61, 1,278.76 and 390.28

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Solution

The fourth proportional to 852.61, 1,278.76 and 390.28 is: 585.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    852.61 : 1,278.76 = 390.28 : x
  2. Step 2: Convert to fraction form
    852.61/1,278.76 = 390.28/x
  3. Step 3: Cross multiply
    852.61x = 1,278.76 × 390.28
  4. Step 4: Simplify right side
    852.61x = 499,074.45
  5. Step 5: Solve for x
    x = 499,074.45/852.61
  6. Step 6: Final answer
    x = 585.35

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1.5x scale

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.