In a study of lettuce growth. 10 seedlings were randomly allocated to be grown in either standard nutrient solution or in a solution containing extra nitrogen. After 22 days of growth, the plants were harvested and weighed, with the results given in the table. Are the data sufficient to conclude that the extra nitrogen enhances plant growth under these conditions? Use a t test at a 0.10 against a directional alternative. (Assume that the data are normally distributed.)


(a) What is the value of the t test statistic for comparing the means?
(b) The P-value for the t test is 0.096. If α = 0.10, what is your conclusion regarding H0?