Suppose That a Normal Model Describes the Acidity $( \mathrm { pH } )$

Multiple Choice

Suppose that a Normal model describes the acidity $( \mathrm { pH } )$ of rainwater, and that water tested after last week's storm had a z-score of $1.8$ . This means that the acidity of that rain ...

A) varied with a standard deviation of $1.8$ .
B) had a pH $1.8$ higher than average rainfall.
C) had a pH $1.8$ standard deviations higher than that of average rainwater.
D) had a $\mathrm { pH }$ of $1.8$ .
E) had a pH $1.8$ times that of average rainwater.