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Finding the Fourth Proportional to 558.40, 770.61 and 309.75

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Solution

The fourth proportional to 558.40, 770.61 and 309.75 is: 427.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    558.40 : 770.61 = 309.75 : x
  2. Step 2: Convert to fraction form
    558.40/770.61 = 309.75/x
  3. Step 3: Cross multiply
    558.40x = 770.61 × 309.75
  4. Step 4: Simplify right side
    558.40x = 238,696.45
  5. Step 5: Solve for x
    x = 238,696.45/558.40
  6. Step 6: Final answer
    x = 427.46

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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.