Which statements accurately describe the considerations when estimating a population mean with an unknown population standard deviation? (Select all that apply.) Group of answer choices Assuming the population is normally distributed, or the sample size exceeds 30, we use the Student's t-distribution rather than the normal distribution. When the population standard deviation is unknown, we use the sample standard deviation in place of the population standard deviation. Increasing the sample size decreases the standard error of the sample mean and hence decreases the margin of error. This introduces additional uncertainty due to the variability in sample standard deviations. The use of the Student's t-distribution increases the margin of error compared to using the normal