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Finding the Fourth Proportional to 420.76, 580.66 and 243.72

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Solution

The fourth proportional to 420.76, 580.66 and 243.72 is: 336.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.76 : 580.66 = 243.72 : x
  2. Step 2: Convert to fraction form
    420.76/580.66 = 243.72/x
  3. Step 3: Cross multiply
    420.76x = 580.66 × 243.72
  4. Step 4: Simplify right side
    420.76x = 141,517.24
  5. Step 5: Solve for x
    x = 141,517.24/420.76
  6. Step 6: Final answer
    x = 336.34

Related Problems

Find fourth proportional to 210.38, 290.33 and 121.86
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Double scale
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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.