22. 14x
24. 14y+4x
26.8x
28. 7(5x+9y)
30. 7x+(3 x 4) [not sure]
32. 4y & 3y are like terms
5 is a constant
A graphing calculator shows it takes 3.25 seconds for the shoe to hit the building.
_____
200 -16t^2 = 31
169 = 16t^2
√(169/16) = t
t = 13/4 = 3 1/4
Answer: 208.
Step-by-step explanation:
The formula to find the minimum sample size is given by :-
(1)
, where z* = critical z-value (two tailed).
= Standard deviation ( from prior study ) and E = Margin of error.
As per given , we have
Margin of error : E= 0.29
Confidence level = 85%
Significance level =
Using z-table , the critical value (two -tailed)=
As per previous study , Variance =

Now, the required minimum sample size =
[Substitute the values in formula (1)]

[ Round to the next integer]
Hence, the minimum number of third graders that must be included in a sample = 208.
The answer is pretty simple, 1/8, 1/5, 1/4, 1/2