A Sample of 32 Orders for a Home Shopping Channel $\$ 78.25 \pm \$ 37.50$

Multiple Choice

A sample of 32 orders for a home shopping channel has an average of $78.25.The standard deviation for all orders (the population) is $37.50.A 90% confidence interval around this sample mean would be:

A) $\$ 78.25 \pm \$ 37.50$
B) $\$ 78.25 \pm \$ 10.87$
C) $\$ 78.25 \pm \$ 6.63$
D) $\$ 37.50 \pm \$ 6.63$
E) $\$ 37.50 \pm \$ 1.64$