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Finding the Fourth Proportional to 668.99, 921.29 and 666.96

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Solution

The fourth proportional to 668.99, 921.29 and 666.96 is: 918.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.99 : 921.29 = 666.96 : x
  2. Step 2: Convert to fraction form
    668.99/921.29 = 666.96/x
  3. Step 3: Cross multiply
    668.99x = 921.29 × 666.96
  4. Step 4: Simplify right side
    668.99x = 614,460.24
  5. Step 5: Solve for x
    x = 614,460.24/668.99
  6. Step 6: Final answer
    x = 918.50

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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.