Question

The percentage of first year college females who will claim no religious affiliation in 2025 is approximately %

Answer 1

We have to calculate the average increase in the percentage, and the extrapolate it to 2025.

We have the following data:

1980: 6.5%

1990: 10.6%

2000: 13.3%

2012: 21.1%

We can calculate an average value taking into account the year 2012 and the year 1980.

We can do that as:

$\bar{p}=\frac{21.1-6.5}{2012-1980}=\frac{14.6}{32}=0.45625$

In 32 years, the average increase in the percentage is 0.45625%.

Then, we have to extrapolate to the year 2025.

From 2012 we have (2025-2012) = 13 years.

Then, we expect an increase of:

$0.45625\cdot13=5.93195\approx5.9$

From 2012 to 2025 we expect an increase of 5.9%, so we add it to the level of 2012 and we get the level of 2025:

$p_{2025}=21.1+5.9=27.0$

The percentage of first year college females who will claim no religious affiliation in 2025 is approximately 27.0%.