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Finding the Fourth Proportional to 918.99, 1,268.21 and 499.35

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Solution

The fourth proportional to 918.99, 1,268.21 and 499.35 is: 689.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    918.99 : 1,268.21 = 499.35 : x
  2. Step 2: Convert to fraction form
    918.99/1,268.21 = 499.35/x
  3. Step 3: Cross multiply
    918.99x = 1,268.21 × 499.35
  4. Step 4: Simplify right side
    918.99x = 633,280.66
  5. Step 5: Solve for x
    x = 633,280.66/918.99
  6. Step 6: Final answer
    x = 689.11

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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.