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Finding the Fourth Proportional to 715.40, 988.43 and 690.42

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Solution

The fourth proportional to 715.40, 988.43 and 690.42 is: 953.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.40 : 988.43 = 690.42 : x
  2. Step 2: Convert to fraction form
    715.40/988.43 = 690.42/x
  3. Step 3: Cross multiply
    715.40x = 988.43 × 690.42
  4. Step 4: Simplify right side
    715.40x = 682,428.39
  5. Step 5: Solve for x
    x = 682,428.39/715.40
  6. Step 6: Final answer
    x = 953.92

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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.