Write an equation that fits the data given I only need help

Write an equation that fits the data given. I only need help with 20-23.

The data given Mow show conversions between miles per hour and kilometers per hour. Based on this data, graph a conversion line cm the Cartesian plane. What would be the approximate conversion of 9 mph to kph? = 14 What would be the approximate conversion of 13 kph to mph = 8 A bicyclist travels 12 mph downhill. Approximately how many kph is the bicyclist traveling? = Write an equation that fits the data given. Assume the data is linear. Paulo turned on the oven to preheat it. After one minute, the oven temperature was 200 degree. After 2 minutes, the oven temperature was 325 degree. Assuming the oven temperature rose at a constant rate, write an equation that fits the data. Compare the relationships in each question below. (DOK 3) Which cab company charges more for 6 miles, Orange Cab or Red Cab? (x is the number of miles driven and y is the total cost) Red Cab: y = 2x + 3 Which electric company should Michael choose to have a cheaper electric bill, Electric Company A or Electric Company B? (xis the rate for each unit of power consumed and y is the total monthly charges) Electric Company B: y 0.02x + 25

Solution

20 )

Given that data is linear

assume equation is y = ax +b

where y=charges x = hours and a and b are constant need to be find out

applying first condition

170 = a + b-----------------------(1)

applying 2nd conditions

220=2a + b ------------------------ (2)

eq (2)- eq(1) we get

220-170 = a a= 50

put value of a in eq (1)

we get

170 = 50 + b

b= 120

therefore equation to fit given data is y=50x+120

21)

Let tempearture of oven can be modeled as

y=ax+b

where y is in temperature

x is in minutes

and a and b are constant need to be find out

applying given two conditions we get 2 equation

220=a+b----------------(1)

325=2a+b----------------(2)

now

eq(2) -eq(1)

325-220=a a= 105

putting these value in eq (1)

we get

b=115

therefore

equation of given model is

y=105x+115

22) from the graph

its clear that when x=6 miles then orange cab cost is 17

also for red cab

y=2x+ 3 for x=6 y= 2*6+3 = 15

Hence Orange cab cost is more

23)

let model the company A as y = mx+c

applying conditions

30.40=10 m + c

30.60= 15m+c

solving these equation we get

m=0.04 c=30

therefore

y= 0.04x+30

thus company A rate of increment is 0.04 while that for company B is 0.02 Hence Company B is cheaper