Step-by-step explanation:
(i) 2x = 5
compare with ax+by+c = 0
→ 2x + 0.y - 5 = 0
» a = 2 ,b = 0 ,c = -5
(ii) y - 2 = 0
compare with ax + by + c = 0
→ 0.x + 1y -2 = 0
» a = 0 , b = 1 , c = -2
(iii) y/7 = 3
y = 3×7
y = 21
y - 21 = 0
compare with ax + by + c = 0
→ 0.x + 1y -21 = 0
» a = 0 , b = 1 , c = -21
(iv). x = -14/13
13x = -14
13x + 14 = 0
compare with ax + by + c = 0
→ 13x + 0.y + 14 = 0
» a = 13 , b = 0 , c = 14
8.5cm · 250,000 = 2,125,000cm
1m = 100cm therefore 1cm = 0.01m
2,125,000cm = 2,125,000 · 0.01 = 21,250m
1km = 1,000m therefore 1m = 0.001km
21,250m = 21,250 · 0.001km = 21.25km
Answer: 21,250m = 21,25km
Answer:
The minimum number of cities we need to contact is 96.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence interval
, we have the following confidence interval of proportions.

In which
Z is the zscore that has a pvalue of
.
The margin of error is:

95% confidence interval
So
, z is the value of Z that has a pvalue of
, so
.
In this problem, we have that:







The minimum number of cities we need to contact is 96.
Answer:
Step-by-step explanation:
=-9+7i+5+i
=-4+8i