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Finding the Fourth Proportional to 421.19, 581.48 and 320.81

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Solution

The fourth proportional to 421.19, 581.48 and 320.81 is: 442.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.19 : 581.48 = 320.81 : x
  2. Step 2: Convert to fraction form
    421.19/581.48 = 320.81/x
  3. Step 3: Cross multiply
    421.19x = 581.48 × 320.81
  4. Step 4: Simplify right side
    421.19x = 186,547.69
  5. Step 5: Solve for x
    x = 186,547.69/421.19
  6. Step 6: Final answer
    x = 442.91

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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.