15 less then then the product of five and x

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?

Which inequality is equivalent to -3x < -12? x < 4 , x < -4 , x > 4, x > -4

I’m really confused and need to learn this