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Finding the Fourth Proportional to 521.39, 719.66 and 311.70

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Solution

The fourth proportional to 521.39, 719.66 and 311.70 is: 430.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.39 : 719.66 = 311.70 : x
  2. Step 2: Convert to fraction form
    521.39/719.66 = 311.70/x
  3. Step 3: Cross multiply
    521.39x = 719.66 × 311.70
  4. Step 4: Simplify right side
    521.39x = 224,319.75
  5. Step 5: Solve for x
    x = 224,319.75/521.39
  6. Step 6: Final answer
    x = 430.24

Related Problems

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Half scale
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Double scale
Find fourth proportional to 522.39, 721.04 and 312.70
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.