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Finding the Fourth Proportional to 1,140.65, 1,574.07 and 643.34

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Solution

The fourth proportional to 1,140.65, 1,574.07 and 643.34 is: 887.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,140.65 : 1,574.07 = 643.34 : x
  2. Step 2: Convert to fraction form
    1,140.65/1,574.07 = 643.34/x
  3. Step 3: Cross multiply
    1,140.65x = 1,574.07 × 643.34
  4. Step 4: Simplify right side
    1,140.65x = 1,012,663.72
  5. Step 5: Solve for x
    x = 1,012,663.72/1,140.65
  6. Step 6: Final answer
    x = 887.80

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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.