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Finding the Fourth Proportional to 870.40, 1,298.33 and 788.32

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Solution

The fourth proportional to 870.40, 1,298.33 and 788.32 is: 1,175.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.40 : 1,298.33 = 788.32 : x
  2. Step 2: Convert to fraction form
    870.40/1,298.33 = 788.32/x
  3. Step 3: Cross multiply
    870.40x = 1,298.33 × 788.32
  4. Step 4: Simplify right side
    870.40x = 1,023,499.51
  5. Step 5: Solve for x
    x = 1,023,499.51/870.40
  6. Step 6: Final answer
    x = 1,175.90

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.