The single-sample t-test compares the mean of the sample to a given number (which you supply). The dependent-sample t-test compares the difference in the means from the two variables to a given number (usually 0), while taking into account the fact that the scores are not independent.The independent samples t-test compares the difference in the means from the two groups to a given value (usually 0).he single sample t-test tests the null hypothesis that the population mean is equal to the given number specified using the option H0=. In our example, the t-value for variable write is 4.14 with 199 degrees of freedom.
Vermont had the second-highest median age, at 42.3 years. New Hampshire was third, with a median age of 42. Utah was the youngest state, with a median age of 29.9 years. Officials say among Maine counties, Lincoln is the oldest with a median age of 49.4 years. Androscoggin County was the youngest, at 40.5 years.
1 Japan has the oldest population in the world, with 23.3% aged over 65 in January 2011 and a life expectancy at birth of 83.1 years in 2010, the highest in the world. Western Europe is the region with the worldâs oldest population (as a proportion of the total population), with 16.5% of people aged over 65 in January 2011.