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Finding the Fourth Proportional to 1,090.85, 1,505.38 and 642.81

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Solution

The fourth proportional to 1,090.85, 1,505.38 and 642.81 is: 887.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,090.85 : 1,505.38 = 642.81 : x
  2. Step 2: Convert to fraction form
    1,090.85/1,505.38 = 642.81/x
  3. Step 3: Cross multiply
    1,090.85x = 1,505.38 × 642.81
  4. Step 4: Simplify right side
    1,090.85x = 967,671.71
  5. Step 5: Solve for x
    x = 967,671.71/1,090.85
  6. Step 6: Final answer
    x = 887.08

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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.