A Large National Bank Charges Local Companies for Using Their $$E ( y ) = \beta _ { 0 } + \beta _ { 1 } x$$

A large national bank charges local companies for using their services. A bank official reported the results of a regression analysis designed to predict the bankʹs charges (y) , measured in dollars per
Month, for services rendered to local companies. One independent variable used to predict service
Charge to a company is the companyʹs sales revenue (x) , measured in $ million. Data for 21
Companies who use the bankʹs services were used to fit the model $$E ( y ) = \beta _ { 0 } + \beta _ { 1 } x$$
Suppose a $95 \%$ confidence interval for $\beta _ { 1 }$ is $( 15,25 )$ . Interpret the interval.

A) We are $95 \%$ confident that sales revenue $( x )$ will increase between $\$ 15$ and $\$ 25$ million for every $\$ 1$ increase in service charge $( y )$ .
B) We are $95 \%$ confident that the mean service charge will fall between $\$ 15$ and $\$ 25$ per month.
C) We are $95 \%$ confident that service charge $( y )$ will increase between $\$ 15$ and $\$ 25$ for every $\$ 1$ million increase in sales revenue $( x )$ .
D) We are $95 \%$ confident that service charge $( y )$ will decrease between $\$ 15$ and $\$ 25$ for every $\$ 1$ million increase in sales revenue $( x )$ .