Home / 913.60-1,370.40-860.80

Finding the Fourth Proportional to 913.60, 1,370.40 and 860.80

Calculator

Solution

The fourth proportional to 913.60, 1,370.40 and 860.80 is: 1,291.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    913.60 : 1,370.40 = 860.80 : x
  2. Step 2: Convert to fraction form
    913.60/1,370.40 = 860.80/x
  3. Step 3: Cross multiply
    913.60x = 1,370.40 × 860.80
  4. Step 4: Simplify right side
    913.60x = 1,179,640.32
  5. Step 5: Solve for x
    x = 1,179,640.32/913.60
  6. Step 6: Final answer
    x = 1,291.20

Related Problems

Find fourth proportional to 456.80, 685.20 and 430.40
Half scale
Find fourth proportional to 1,827.20, 2,740.80 and 1,721.60
Double scale
Find fourth proportional to 914.60, 1,371.90 and 861.80
Similar ratio
Find fourth proportional to 1,370.40, 2,055.60 and 1,291.20
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.