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Finding the Fourth Proportional to 777.40, 1,166.20 and 387.60

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Solution

The fourth proportional to 777.40, 1,166.20 and 387.60 is: 581.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.40 : 1,166.20 = 387.60 : x
  2. Step 2: Convert to fraction form
    777.40/1,166.20 = 387.60/x
  3. Step 3: Cross multiply
    777.40x = 1,166.20 × 387.60
  4. Step 4: Simplify right side
    777.40x = 452,019.12
  5. Step 5: Solve for x
    x = 452,019.12/777.40
  6. Step 6: Final answer
    x = 581.45

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.