A health care professional wants to determine whether individuals with hypertension who take Atenololhave 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 153 (= 153) with a standard deviation of 19.The 256 individuals who take Atenololhave an average (mean) systolic blood pressure of 122.On the basis of these data, can the researcher conclude that the Atenololsignificantly 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)