Answer:
see explanation
Step-by-step explanation:
x = r cosΘ
y = r sinΘ
with r = 54 and Θ = 69°, thus
x = 54cos69° ≈ 19.4
y = 54sin69° ≈ 50.4
Thus (54, 69° ) as an ordered pair
= ![\left[\begin{array}{ccc}19.4\\50.4\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D19.4%5C%5C50.4%5C%5C%5Cend%7Barray%7D%5Cright%5D)
The formula for Average speed = 
The car travels 80 km in 1 hour.
Then the car travels 90 km in 2 hours.
And finally the car travels 76 km in 1 hour
So the total distance covered by the car = 80 + 90 + 76 = 246 km
The total time taken to cover this distance = 1 + 2 + 1 = 4 hours.
So average speed = 
The average speed of the car is 61.5 km / h
Answer:
r = -1
Step-by-step explanation:
(y2-y1)/(x2-x1)=m
(r,7)=(x1,y1) and (3,4)=(x2-y2) and m=-3/5
so plug in...
(4-7)/(4-r)=-3/5
then solve for r which will get that r = -1
numerator: 4-7=-3
denominator: 4-r=5 -> 4-5=0+r -> -1=r
16 is the rational number, hope this is helpful
Okay, so the formula for a confidence interval is
test statistic +/- (critical value)(standard deviation of statistic
44 +/- (invNorm(area: 0.05, u=0, std:1))(14.5)
44 +/- 23.85
(20.15, 67.85)
hope this helps :)