A variable has a mean of 100 and a standard deviation of 8. Four observations of this variable have a mean of 113 and a sample standard deviation of 6. Determine the observed value of thea. standardized version ofb. studentized version of

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60