A) The question would be "Does cell phone use time correlate to brain cancer?". The population is all cell phone users. The sample is the 469 people with brain cancer, and the 422 healthy people.
B) This sample size may not portray the entire population of users because the positive results may have been fabricated by factors other than cell phone use. You would have to figure out the population size and determine the correct sample size.
C) This study may not portray cell phone use correlation over a large population efficiently because of the sample size and the predetermined conclusion that cell phone use causes cancer.
If the axis of symmetry is x=-1, the vertex will have x-coordinate -1.
The point (0, 5) cannot be the vertex. The friend is not correct.
_____
If the point (1, 5) is on the graph so is the image of that point when it is reflected across the axis of symmetry. That image point is (-3, 5). A parabola that goes through points (1, 5) and (-3, 5) will not go through point (0, 5).
Step-by-step explanation:
last week there were 19+30+77 = 126 customers.
19/126 = 1/14 paid cash.
30/126 = 5/21 paid by debit card.
77/126 = 11/18 paid by credit card.
next week he expects 1800 customers.
that is compared to 126 a factor of
1800/126 = 300/21 = 100/7
now we actually only need to apply the same factor to any part of the total sum to get their share in the new total sum.
it simply follows the rule
(a + b + c) × d = ad + bd + cd
so,
77 × 100/7 = 11 × 100 = 1100 customers are expected to pay per credit card.
Sec is 1/cos so sec -120 is 1/cos -120 which is -2
