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Finding the Fourth Proportional to 420.64, 580.20 and 254.76

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Solution

The fourth proportional to 420.64, 580.20 and 254.76 is: 351.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.64 : 580.20 = 254.76 : x
  2. Step 2: Convert to fraction form
    420.64/580.20 = 254.76/x
  3. Step 3: Cross multiply
    420.64x = 580.20 × 254.76
  4. Step 4: Simplify right side
    420.64x = 147,811.75
  5. Step 5: Solve for x
    x = 147,811.75/420.64
  6. Step 6: Final answer
    x = 351.40

Related Problems

Find fourth proportional to 210.32, 290.10 and 127.38
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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.