A health care professional wants to determine whether individuals with hypertension who take Atenolol have significantly lower systolic blood pressure than individuals with hypertension who do not take Atenolol. For individuals who have not been prescribed Atenolol, the population systolic blood pressure mean is 150 ( = 150).The 251 individuals who take Atenolol have an average systolic blood pressure of 121, with asample standard deviationof 4.On the basis of these data, can the researcher conclude that the Atenolol significantly lowers systolic blood pressure?

What is the z-value or t-value you obtained (your test statistic)?(numeric value only, including negative sign if required)