Home / 7.80-11.65-6

Finding the Fourth Proportional to 7.80, 11.65 and 6

Calculator

Solution

The fourth proportional to 7.80, 11.65 and 6 is: 8.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.80 : 11.65 = 6 : x
  2. Step 2: Convert to fraction form
    7.80/11.65 = 6/x
  3. Step 3: Cross multiply
    7.80x = 11.65 × 6
  4. Step 4: Simplify right side
    7.80x = 69.90
  5. Step 5: Solve for x
    x = 69.90/7.80
  6. Step 6: Final answer
    x = 8.96

Related Problems

Find fourth proportional to 3.90, 5.83 and 3
Half scale
Find fourth proportional to 15.60, 23.30 and 12
Double scale
Find fourth proportional to 8.80, 13.14 and 7
Similar ratio
Find fourth proportional to 11.70, 17.48 and 9
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.