Hello! Seeings 20 is less than 50, you then need to round down. If its over 50 then you round up! So if you have 14 its rounded to 10. And if you have 16 round it to 20. So 820 is rounded to 800.
Answer:
(a) The data set is a function, since for each input value {3,4,6,11} there is a single output value {5,7,11,21}
(B) A function is a mathematical relationship that associates one or more inputs with a single output value. So that the data set is not a function, there should be - for one or more values of the input - more than one output.
for example, if for the input value {3} there were two outputs {5, -5} then, the data set would not be a function.
The frelation
is not a function because:
When x = 1, y = +1 and y = -1.
(c) The set of data provided can be represented by the equation of a line of the form y = mx + b
The slope is:


m = 2

b = 5 - 2*3
b = -1
Then, the function is:
y = 2x-1
You can substitute any of the points shown in the equation and check that equality is satisfied, for example:
(11 , 21)
y = 2 (11) -1
y = 22-1
y = 21. The equation is satisfied. The same goes for the rest of the values.
First of all work out how many tom and scott sold.
tom sold 60% of 90 cookies which is 54.
scott sold 2/3 of 150 cookies which is 100.
altogether the three of them sold 54+100+46 cookies which is 200.
Dawn sold 46 of these 200 cookies. To work out the percentage we have both the numbers to get 23 out of 100. We halved those numbers because a percentage is out of 100 we halved it to get it out of 100.
so 23 out of 100 is 23% so dawn sold 23%of the cookies.
Hope this helps :)