Isosceles Right
Isosceles, since the two side lengths are equal, and it is a right triangle since it has a 90 degree angle and two other 45 degree angles.
Answer: (0.00306,0.00334)
Step-by-step explanation:
Given : Sample size : n= 420000
The number of users developed cancer of the brain or nervous system =134
Then , the proportion of users developed cancer of the brain or nervous system :
Significance level : 
Critical value : 
The confidence interval for population proportion is given by :-
Hence, the 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system is (0.00306,0.00334).
Given that the arc length is 4.189 cm and the radius is 3 cm, the size of the arc will found as follows;
C=theta/360 πd
suppose:
size of arc=theta=x
d=3*2=6 cm
hence;
4.189=x/360*π*6
4.189=0.0524x
x=4.189/0.0524
x=80.004°
The size of the arc length is 80.004°
Let x represent the number of half-gallons purchased by the store. Then x-13 is the number sold, and 2.80x is the store's cost. The revenue is 4.06(x-13) and the difference between that and cost is the profit.
... 4.06(x -13) -2.80x = 63.14
... 1.26x - 52.78 = 63.14 . . . . eliminate parentheses, collect terms
... 1.26x = 115.92 . . . . . . . . . . add 52.78
... x = 115.92/1.26 = 92 . . . . . divide by the coefficient of x
The store purchased 92 half-gallons of milk.
