Cheryl wants to find the number of hours seventh-graders do homework each week. There are 297 boys and girls in seventh grade. If Cheryl randomly surveyed 50 girls in the entire school to find the number of hours seventh-graders do homework each week, describe why she would get a biased sample. Cheryl wants to find the number of hours seventh-graders do homework each week. There are 297 boys and girls in seventh grade. If Cheryl randomly surveyed 50 girls in the entire school to find the number of hours seventh-graders do homework each week, describe why she would get a biased sample.

It is because she only surveyed 50 girls. There are two problems. In total, there are 297 students so she practically just surveyed 16.8% of the students in the year group. She only surveyed girls and did not survey the boys. This survey only included girls and not the boys in the seventh grade - inaccurate and unreliable.  

Step-by-step explanation:

I'm not sure about my answer but I just want to give you some ideas... sorry if this did not help you :(( hope it does, tho!

a) 40 more; b) old factory:   10%, new factory:   16%; c) week 4

explanation:

a) at week 0, we see in the graph that the new factory produces 190 specialty items.  

using the function, substituting 0 in for w,

this is a difference of 230-190 = 40.

b) the function for the old factory is written in the form f(x) = a(1+r)ˣ, where a is the original amount, x is the amount of time and r is the growth rate.   the equation for the old factory is ; 230 is in place of a and is the original amount; w is the amount of time; which means 1+r = 1.1.   this means that r must be 0.1 or 10%.

for the new factory, we find the percent of increase to find the growth rate; the formula for this is

between the first two points, the amount of change is 220-190 = 30; this gives us

30/190 = 0.158 ≈ 0.16 = 16%

c) at week 0, the old factory has 230 while the new factory has 190.

at week 1, the old factory has 230(1.1) = 253 while the new factory has 220.

at week 2, the old factory has 230(1.1²) = 278.3 while the new factory has 252.

at week 3, the old factory has 230(1.1³) = 306.13 while the new factory has 290.

at week 4, the old factory has 230(1.1⁴) = 336.743 while the new factory has 337.   this is the first week that the new factory surpasses the old.