Which is the directrix of a parabola with equation x^2=4y

The mean of a set of data is -3.82 and its standard deviation is 2.31. find the z score for a value of 3.99.

Daniel expanded the expression as shown below -2(-8x-4y+3/4)=-10x-8y-11/4 what errors did he make? check all that apply

The marked price of an article is 25% above its selling price and the cost price is 30% less than its marked price . find the discount percent and gain percent. only a brainlest can solve it i will mark you brainlest