Question 1077402
Standard Error = SE
SE = s/sqrt(n)
SE = 7.73/sqrt(24)
SE = 1.57787964264283


Standard Z score
z = (x - mu)/SE
z = (70-73)/1.57787964264283
z = -1.9012856994436
z = -1.90


Now use <a href = "http://www.stat.ufl.edu/~athienit/Tables/Ztable.pdf">a table</a> to find the area to the left of z = -1.90
With that table, look at the row that has -1.9 and the column with 0.00. The intersection of this row and column combo has 0.0287 in the cell


This means that
P(Z < -1.90) = 0.0287
P(xbar < 70) = 0.0287
This is approximate of course. To get better accuracy, a calculator is recommended. 


Since the area is 0.0287, the percentage of sample means less than 70 is roughly <font color=red>2.87%</font> which is the final answer.