Home / 783.49-1,078.76-665.22

Finding the Fourth Proportional to 783.49, 1,078.76 and 665.22

Calculator

Solution

The fourth proportional to 783.49, 1,078.76 and 665.22 is: 915.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.49 : 1,078.76 = 665.22 : x
  2. Step 2: Convert to fraction form
    783.49/1,078.76 = 665.22/x
  3. Step 3: Cross multiply
    783.49x = 1,078.76 × 665.22
  4. Step 4: Simplify right side
    783.49x = 717,609.40
  5. Step 5: Solve for x
    x = 717,609.40/783.49
  6. Step 6: Final answer
    x = 915.91

Related Problems

Find fourth proportional to 391.75, 539.38 and 332.61
Half scale
Find fourth proportional to 1,566.98, 2,157.51 and 1,330.44
Double scale
Find fourth proportional to 784.49, 1,080.13 and 666.22
Similar ratio
Find fourth proportional to 1,175.24, 1,618.13 and 997.83
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.