The first x is the horizontal coodinate (abscisa) and second is the vertical coordinate (ordenate). Both are coordinates. (x,y) has the meaning of a complex number: x is the real part and y is the imaginary part: x+yi. (x,y) has the meaning of a plane's vector from origin of coordinates.
Answer:

Step-by-step explanation:
Part (a) the probability that two people have a birthday on the 9th of any month.
Neglecting leap year, there are 365 days in a year.
There are 12 possible 9th in months that make a year calendar.
If two people have birthday on 9th; P(1st person) and P(2nd person).

Part (b) the probability that two people have a birthday on the same day of the same month
P(2 people selected have birthday on the same day of same month) + P(2 people selected not having birthday on same day of same month) = 1
P(2 people selected not having birthday on same day of same month):

P(2 people selected have birthday on the same day of same month) 
About 3.8 hours, if asking for a whole number round to 4
Answer:
the minimum sample size n = 11.03
Step-by-step explanation:
Given that:
approximate value of the population standard deviation
= 49
level of significance ∝ = 0.01
population mean = 38
the minimum sample size n = ?
The minimum sample size required can be determined by calculating the margin of error which can be re[resented by the equation ;
Margin of error = 





n ≅ 11.03
Thus; the minimum sample size n = 11.03
$5,796 is how much it would be. hope it helps