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Finding the Fourth Proportional to 556.76, 769.08 and 390.86

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Solution

The fourth proportional to 556.76, 769.08 and 390.86 is: 539.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    556.76 : 769.08 = 390.86 : x
  2. Step 2: Convert to fraction form
    556.76/769.08 = 390.86/x
  3. Step 3: Cross multiply
    556.76x = 769.08 × 390.86
  4. Step 4: Simplify right side
    556.76x = 300,602.61
  5. Step 5: Solve for x
    x = 300,602.61/556.76
  6. Step 6: Final answer
    x = 539.91

Related Problems

Find fourth proportional to 278.38, 384.54 and 195.43
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Double scale
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Similar ratio
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1.5x scale

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.