Question

The pipe fitting industry had 546.5 thousand jobs in 2015 and is expected to decline at an average rate of 3 thousand jobs per year from 2015 to 2025. Assuming this holds true, what will be the pipe fitting's percent change from 2015 to 2025

Answer 1

The amount of jobs from fitting industry shall decline in 5.5 percent from 2015 to 2025.

Explanation:

Due to the assumption of a yearly average rate, a linear function model shall be used. The expected amount of jobs (
`n`) after a certain amount of years (t) is given by the following formula:

`n = n_(o) + (\Delta n)/(\Delta t)\cdot t`

Where:

`n_(o)` - Initial amount of jobs in pipe fitting industry, measured in thousands.

`(\Delta n)/(\Delta t)` - Average yearly rate, measured in thousands per year. (A decline is indicated by a negative sign)

If
`n_(o) = 546.5`,
`t = 2025-2015 = 10\,years` and
`(\Delta n)/(\Delta t) = -3\,(1)/(years)`, then:

`n = 546.5+\left(-3\,(1)/(year)\right)\cdot (10\,years)`

`n = 516.5`

The percent change in jobs from pipe fitting industry is calculated as follows:

`\%n = \left(1-(n)/(n_(o))\right)* 100\,\%`

`\% n = \left(1-(516.5)/(546.5)\right)* 100\,\%`

`\%n = 5.5\,\%`

The amount of jobs from fitting industry shall decline in 5.5 percent from 2015 to 2025.