A student has gotten the following grades on his tests. What is the minimum grade he must get on the last test in order to have an average of 80?
73. 87, 85, 70

85%

Step-by-step explanation:

To find his average you add all his scores together and divide it by the number of scores there are. So 73+87+85+70+85=80, and that will be his average if he gets an 85% on his last test.

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

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1