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Finding the Fourth Proportional to 1,438.80, 1,985.04 and 817.68

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Solution

The fourth proportional to 1,438.80, 1,985.04 and 817.68 is: 1,128.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,438.80 : 1,985.04 = 817.68 : x
  2. Step 2: Convert to fraction form
    1,438.80/1,985.04 = 817.68/x
  3. Step 3: Cross multiply
    1,438.80x = 1,985.04 × 817.68
  4. Step 4: Simplify right side
    1,438.80x = 1,623,127.51
  5. Step 5: Solve for x
    x = 1,623,127.51/1,438.80
  6. Step 6: Final answer
    x = 1,128.11

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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.