Home / 147.40-221.11-78.80

Finding the Fourth Proportional to 147.40, 221.11 and 78.80

Calculator

Solution

The fourth proportional to 147.40, 221.11 and 78.80 is: 118.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    147.40 : 221.11 = 78.80 : x
  2. Step 2: Convert to fraction form
    147.40/221.11 = 78.80/x
  3. Step 3: Cross multiply
    147.40x = 221.11 × 78.80
  4. Step 4: Simplify right side
    147.40x = 17,422.17
  5. Step 5: Solve for x
    x = 17,422.17/147.40
  6. Step 6: Final answer
    x = 118.20

Related Problems

Find fourth proportional to 73.70, 110.55 and 39.40
Half scale
Find fourth proportional to 294.80, 442.22 and 157.59
Double scale
Find fourth proportional to 148.40, 222.61 and 79.80
Similar ratio
Find fourth proportional to 221.10, 331.66 and 118.19
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.