Home / 253.40-380.05-82.40

Finding the Fourth Proportional to 253.40, 380.05 and 82.40

Calculator

Solution

The fourth proportional to 253.40, 380.05 and 82.40 is: 123.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.40 : 380.05 = 82.40 : x
  2. Step 2: Convert to fraction form
    253.40/380.05 = 82.40/x
  3. Step 3: Cross multiply
    253.40x = 380.05 × 82.40
  4. Step 4: Simplify right side
    253.40x = 31,314.22
  5. Step 5: Solve for x
    x = 31,314.22/253.40
  6. Step 6: Final answer
    x = 123.58

Related Problems

Find fourth proportional to 126.70, 190.03 and 41.20
Half scale
Find fourth proportional to 506.79, 760.10 and 164.79
Double scale
Find fourth proportional to 254.40, 381.55 and 83.40
Similar ratio
Find fourth proportional to 380.09, 570.08 and 123.59
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.