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Finding the Fourth Proportional to 870.80, 1,298.86 and 810.32

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Solution

The fourth proportional to 870.80, 1,298.86 and 810.32 is: 1,208.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.80 : 1,298.86 = 810.32 : x
  2. Step 2: Convert to fraction form
    870.80/1,298.86 = 810.32/x
  3. Step 3: Cross multiply
    870.80x = 1,298.86 × 810.32
  4. Step 4: Simplify right side
    870.80x = 1,052,492.24
  5. Step 5: Solve for x
    x = 1,052,492.24/870.80
  6. Step 6: Final answer
    x = 1,208.65

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1.5x scale

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.