1) A psycho-linguist has been studying the frequency of text-speech (e.g., R UOk?, LOL ) has been progressing into EMAIL correspondence.He collects a sample of 121 email messages and computes the mean (average) number of examples of text-speech per message.He also has a huge library of archived email messages from the year 2001.From these he is able to calculate the population average and standard deviation.Compute a inferential statistic to evaluate the hypothesis that the use of text-speech hasincreasedin the years since 2001.Use an alpha level that would insure a maximum of a %5 risk of rejecting a true null hypothesis.

These are the obtained values:

Population Mean from2001:1.5

Population Standard deviation from2001:1.21

Sample mean from thisyear:1.98

a) The appropriatestatistics to use is a ___ test.

b) Calculate and properly report your calculated statistic, and interpretyour conclusion in one or two sentences.