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Finding the Fourth Proportional to 589.40, 812.81 and 390.14

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Solution

The fourth proportional to 589.40, 812.81 and 390.14 is: 538.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    589.40 : 812.81 = 390.14 : x
  2. Step 2: Convert to fraction form
    589.40/812.81 = 390.14/x
  3. Step 3: Cross multiply
    589.40x = 812.81 × 390.14
  4. Step 4: Simplify right side
    589.40x = 317,109.69
  5. Step 5: Solve for x
    x = 317,109.69/589.40
  6. Step 6: Final answer
    x = 538.02

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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.