Standard deviation and variance are used with a. nominal data. ...

[futuristic]

Standard deviation and variance are used with
 
  a. nominal data.
  b. ordinal data.
  c. skewed interval or ratio data.
  d. interval or ratio data with no obvious skew.

Question 2

The fact that the normal distribution is asymptotic to the abscissa means
  that
 
  a. its curve must be symmetrical
  b. its curve must yield both positive and negative values
  c. its curve may never touch the abscissa
  d. its curve must always touch the abscissa

[Galvarado142]

Answer to Question 1

d

Answer to Question 2

c