OKAY, so I'm going to start with Q2 (not 100% sure how to work out 1, but lets use process of elimination). Firstly, the rule is y=mx+c So, start with the first line y=2x-3, from this the first thing you need to do is find the y-intercept (m) and the gradient (c). So, this is very simple 2 is m and -3 is c (if you look at the rule it matches up). m=2/1(this is rise/run, rise is how much you go up by, and run is how much you go left or right by (left if positive, right if negative)) c=-3 Now, go to your graph, and look on the y line and go to -3. Then go left, 1, and up 2. IS THERE A LINE CROSSING THROUGH THIS POINT? Yes? Good. Now for y=-1/2+1. Looking at the rule again (y=mx+c), m=-1/2 (rise/run) c=1 NOW, once again go to your graph, and look on the y line and go to 1 (in this case the line actually passes through this point), now go right 2 places and up 1. IS THERE A LINE? Yes? Good!
NOOOW, for Q3, use the same steps and you will have the answer. y=1/4x-2 m=1/4 (rise/run) c=-2 Look at graph C, start at -2 on the y line, go left 4, and up 1? Yes? Line crossing through this point? good!! Now for the 2nd one, y= -2/5x+4 m=-2/3 c=4 Look at the same graph start at 4 on the y line, go right 5 and up 2! Got it? There's a line crossing through this point, yes? YAY
Now I have no idea how to do Q1, but by process of elimination it's pretty obvious. I hope this is right! Okay, bye!! :D
The cable TV company whats to know what sample size to take to estimate the proportion/percentage of cable boxes in use during an evening hour.
They estimated a "pilot" proportion of p'=0.20
And using a 90% confidence level the CI should have a margin of error of 2% (0.02).
The CI for the population proportion is made using an approximation of the standard normal distribution, and its structure is "point estimation" ± "margin of error"
[p' ± ]
Where
p' is the sample proportion/point estimator of the population proportion
is the margin of error (d) of the confidence interval.