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Finding the Fourth Proportional to 520.76, 718.65 and 287.90

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Solution

The fourth proportional to 520.76, 718.65 and 287.90 is: 397.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.76 : 718.65 = 287.90 : x
  2. Step 2: Convert to fraction form
    520.76/718.65 = 287.90/x
  3. Step 3: Cross multiply
    520.76x = 718.65 × 287.90
  4. Step 4: Simplify right side
    520.76x = 206,899.34
  5. Step 5: Solve for x
    x = 206,899.34/520.76
  6. Step 6: Final answer
    x = 397.30

Related Problems

Find fourth proportional to 260.38, 359.33 and 143.95
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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.