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Finding the Fourth Proportional to 714.95, 986.76 and 420.20

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Solution

The fourth proportional to 714.95, 986.76 and 420.20 is: 579.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.95 : 986.76 = 420.20 : x
  2. Step 2: Convert to fraction form
    714.95/986.76 = 420.20/x
  3. Step 3: Cross multiply
    714.95x = 986.76 × 420.20
  4. Step 4: Simplify right side
    714.95x = 414,636.55
  5. Step 5: Solve for x
    x = 414,636.55/714.95
  6. Step 6: Final answer
    x = 579.95

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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.