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Finding the Fourth Proportional to 777.66, 1,160.80 and 685.40

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Solution

The fourth proportional to 777.66, 1,160.80 and 685.40 is: 1,023.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.66 : 1,160.80 = 685.40 : x
  2. Step 2: Convert to fraction form
    777.66/1,160.80 = 685.40/x
  3. Step 3: Cross multiply
    777.66x = 1,160.80 × 685.40
  4. Step 4: Simplify right side
    777.66x = 795,611.73
  5. Step 5: Solve for x
    x = 795,611.73/777.66
  6. Step 6: Final answer
    x = 1,023.08

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.