Answer:
a
Step-by-step explanation:
If the 2 is little and on top of the a, then it's called "nine a squared."
Answer:

Step-by-step explanation:
-Let x be the sample size and n the population size
-The conditions for a one-sample proportion z-test are:
-The sample is randomly selected from the population.
-The sample size is greater than or equal to ten times the population size:

-The expectation np is greater than or equal to 10:

Answer:
20 mph and 4 mph
Step-by-step explanation:
GIVEN: A boat travels upstream for
miles in
hours and returns in
hours traveling downstream in a river.
TO FIND: What is the rate of the boat in still water and the rate of the current.
SOLUTION:
Let the speed of boat in still water be
and speed of current be
.
speed of water in upstream 
speed of water in downstream 
As 


Solving both we get


Hence speed of boat in still water and rate of current is 20mph and 4mph respectively.
1.
a^2+b^2=c^2
easy
a=a
b=13
c=21
a^2+13^2=21^2
a^2+169=441
minus 169 both sides
a^2=272
sqrt both sides
a=16.4924
D is answer
2. same thing
a=18
b=26
18^2+26^2=c^2
324+676=c^2
1000=c^2
sqrt both sides
31.6228=c
C is answer
3.
one way is to plug them in
remember that hypotonuse is longest side
A. 7^2+24^2=25^2, is that true?, yes it is treu
answer is A
4.
legs are 6 and 4
a=6
b=4
c=x
4^2+6^2=x^2
16+36=x^2
52=x^2
sqrt both sides
7.2111=x
7.2=x
5.c=20
a=x
b=14
x^2+14^2=20^2
x^2+196=400
minus 196 both sides
x^2=204
sqrt both sides
x=14.2829
x=14.3
1. D
2. C
3. A
4. 7.2
5. 14.3