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Finding the Fourth Proportional to 509.08, 702.15 and 390.76

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Solution

The fourth proportional to 509.08, 702.15 and 390.76 is: 538.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.08 : 702.15 = 390.76 : x
  2. Step 2: Convert to fraction form
    509.08/702.15 = 390.76/x
  3. Step 3: Cross multiply
    509.08x = 702.15 × 390.76
  4. Step 4: Simplify right side
    509.08x = 274,372.13
  5. Step 5: Solve for x
    x = 274,372.13/509.08
  6. Step 6: Final answer
    x = 538.96

Related Problems

Find fourth proportional to 254.54, 351.08 and 195.38
Half scale
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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.