What ratio equivalent to 12: 21 with lower terms

Let the mean of the population be 38 instances of from 6" - 9" hatchings per nest, and let the standard deviation of the mean be 3. what sample mean would have a confidence level of 95% or a 2.5% margin of error?

Aye asap pls ! markin da brainiest too ! btw da step choices are all add, distribute, divide, n subtract

Which number line correctly shows 0.8 + 0.3?