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Finding the Fourth Proportional to 710.79, 981.35 and 661.78

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Solution

The fourth proportional to 710.79, 981.35 and 661.78 is: 913.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    710.79 : 981.35 = 661.78 : x
  2. Step 2: Convert to fraction form
    710.79/981.35 = 661.78/x
  3. Step 3: Cross multiply
    710.79x = 981.35 × 661.78
  4. Step 4: Simplify right side
    710.79x = 649,437.80
  5. Step 5: Solve for x
    x = 649,437.80/710.79
  6. Step 6: Final answer
    x = 913.68

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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.