Plz help me due in 5 min

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.

Find the gradient of f(x,y,z)equals=left parenthesis x squared plus y squared plus z squared right parenthesis superscript negative 1 divided by 2 baseline plus ln left parenthesis x right parenthesis x2+y2+z2−1/2+ln(xyz) at the point left parenthesis negative 2 comma 1 comma negative 2 right parenthesis(−2,1,−2).

20 da is equal to a. 2,000 cm. b. 2 m. c. 20,000 cm. d. 20,000 mm