Question

the bar graph shows that life expectancy, the number of years newborns are expected to live, in a particular region has increased dramatically since ancient times. find the percent increase in average
average life expectancy (years)
0 10 20 30 40 50 60 70 80
stone age 28
ancient greece 32
middle ages 35
1900 37
1950 54
1980 67
2016 76

Explanation:

Step1: Identify initial and final values

Initial life - expectancy (Stone Age) $a = 28$ years. Final life - expectancy (2016) $b = 76$ years.

Step2: Use percent - increase formula

The percent - increase formula is $\text{Percent Increase}=\frac{b - a}{a}\times100\%$. Substitute $a = 28$ and $b = 76$ into the formula: $\frac{76 - 28}{28}\times100\%=\frac{48}{28}\times100\%$.

Step3: Calculate the result

$\frac{48}{28}\times100\%=\frac{12}{7}\times100\%\approx171.43\%$.

Answer:

Approximately $171.43\%$