Answer:
Part a) The linear model is
![y=1,400+0.15x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gpibk4ap4gkahsidpgzqrdrzw45h3xk9wr.png)
Part b) The amount earned is
![y=\$2,300](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bfrls5af23ovd7id4mw9y1avmq9kbmr3zp.png)
Explanation:
Let
x ----> total meals worth served by Sam in a month
y ----> total earned by Sam in a month
we know that
The total earned by Sam in a month is equal to the base salary plus the total meals worth served by Sam in a month multiplied by the tips averaging in decimal form
Tips average =15%=15/100=0.15
so
![y=1,400+0.15x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gpibk4ap4gkahsidpgzqrdrzw45h3xk9wr.png)
This is a linear equation in slope intercept form
![y=mx+b](https://img.qammunity.org/2020/formulas/mathematics/high-school/8nudzfk4b5l0arb9iixag2w8am6zn99zlr.png)
where
m is the slope or the unit rate
b is the y-intercept or initial value
The slope of unit rate is equal to
![m=0.15](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2vyntuewuw3za6vn47eb4h2d9yhq6vhz3g.png)
The y-intercept or b is equal to
![b=1,400](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bhhss1fspczl2fhhzas2bqxe6lqtqtvl6u.png)
For x=6,000
substitute in the linear equation
![y=1,400+0.15(6,000)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dbpap7m0z0ggqhvmck3rfz4s82iuve6usg.png)
![y=\$2,300](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bfrls5af23ovd7id4mw9y1avmq9kbmr3zp.png)