Why is “3 meals a day” a unit rate? It compares 1 meal to 1 day.
It compares 1 meal to 3 days.
It compares 3 meals to 1 day.
It compares 3 meals to 3 days.

It compares 3 meals to 1 day

Step-by-step explanation:

"3 meals a day" it is saying that there are 3 meals in a day.

3.4 pizzas

step-by-step explanation:

given is a scatter plot showing number of pizzas sold during weeks for different issues of coupon

y represents number of pizzas sold and x number of coupons issued

y is marked verticaly and x horizontally

the trend line is given as

y =3.4x+43

this says that even when no coupon is issued pizzas sold will be 43

and rate of change of pizza sold for 1 unit of coupon = slope = 3.4

i.e. when x increases by 1 unit y increases by 3.4 units

hence for each additional coupon issued 3.4 pizzas more will be sold