Home / 998.80-1,378.34-556.70

Finding the Fourth Proportional to 998.80, 1,378.34 and 556.70

Calculator

Solution

The fourth proportional to 998.80, 1,378.34 and 556.70 is: 768.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.80 : 1,378.34 = 556.70 : x
  2. Step 2: Convert to fraction form
    998.80/1,378.34 = 556.70/x
  3. Step 3: Cross multiply
    998.80x = 1,378.34 × 556.70
  4. Step 4: Simplify right side
    998.80x = 767,312.20
  5. Step 5: Solve for x
    x = 767,312.20/998.80
  6. Step 6: Final answer
    x = 768.23

Related Problems

Find fourth proportional to 499.40, 689.17 and 278.35
Half scale
Find fourth proportional to 1,997.60, 2,756.67 and 1,113.39
Double scale
Find fourth proportional to 999.80, 1,379.71 and 557.70
Similar ratio
Find fourth proportional to 1,498.20, 2,067.50 and 835.04
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.