Answer:
The correct options are 1, 3 and 4.
Step-by-step explanation:
We need to find the expressions whose simplified form is a rational number.
Rational number: If a number is defined in the form of p/q where p and q are integers and q≠0, then it is called a rational number.
For example: 0,2, 4.3 etc.
Irrational number: If a number can not defined in the form of p/q, where p and q are integers and q≠0, then it is called an irrational number.
First expression is

12 is a rational number.
Second expression is

is an irrational number.
Third expression is

21 is a rational number.
Fourth expression is

5 is a rational number.
Therefore, the correct options are 1, 3 and 4.
Answer: B. 0.036
Step-by-step explanation:
Formula for standard error :

, where p = Population proportion and n= sample size.
Let p be the population proportion of the people who favor new taxes.
As per given , we have
n= 170

Substitute these values in the formula, we get

Hence, the standard error of the estimate is 0.036.
∴ The correct answer is OPTION B. 0.036
(2^8 . 5^-5 . 19^0)^-2
using PEMDAS
this = (2^8 * 1/5^5 * 1)^-2
= (5^5 / 2^8)^2
= 5^10 / 2^16
Answer:
125
Step-by-step explanation:
5 x 5 = 25
25 x 5 = 125