How did the person who made the first clock know what time it was?

One of the earliest of all devices to tell time was the sundial. The sundial is looked on as being a form of sun-powered clock. Ancient civilizations such as the Sumerians did have this knowledge, but when the culture died, knowledge was lost along with many other aspects of the civilization unfortunately.

Step-by-step explanation:

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