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Finding the Fourth Proportional to 521.40, 719.09 and 421.77

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Solution

The fourth proportional to 521.40, 719.09 and 421.77 is: 581.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.40 : 719.09 = 421.77 : x
  2. Step 2: Convert to fraction form
    521.40/719.09 = 421.77/x
  3. Step 3: Cross multiply
    521.40x = 719.09 × 421.77
  4. Step 4: Simplify right side
    521.40x = 303,290.59
  5. Step 5: Solve for x
    x = 303,290.59/521.40
  6. Step 6: Final answer
    x = 581.69

Related Problems

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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.