Home / 854.80-1,279.80-768.40

Finding the Fourth Proportional to 854.80, 1,279.80 and 768.40

Calculator

Solution

The fourth proportional to 854.80, 1,279.80 and 768.40 is: 1,150.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    854.80 : 1,279.80 = 768.40 : x
  2. Step 2: Convert to fraction form
    854.80/1,279.80 = 768.40/x
  3. Step 3: Cross multiply
    854.80x = 1,279.80 × 768.40
  4. Step 4: Simplify right side
    854.80x = 983,398.32
  5. Step 5: Solve for x
    x = 983,398.32/854.80
  6. Step 6: Final answer
    x = 1,150.44

Related Problems

Find fourth proportional to 427.40, 639.90 and 384.20
Half scale
Find fourth proportional to 1,709.60, 2,559.60 and 1,536.80
Double scale
Find fourth proportional to 855.80, 1,281.30 and 769.40
Similar ratio
Find fourth proportional to 1,282.20, 1,919.70 and 1,152.60
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.