Answer:
a) We need a sample size of at least 3109.
b) We need a sample size of at least 4145.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is:
99% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
(a) he uses a previous estimate of 25%?
we need a sample of size at least n.
n is found when 
. So
We need a sample size of at least 3109.
(b) he does not use any prior estimates?
When we do not use any prior estimate, we use 
So
Rounding up
We need a sample size of at least 4145.
Answer:
The statements are incorrect as: The sum of even numbers from 1 to 100(i.e. 2550) is not double\twice of the sum of odd numbers from 1 to 100(i.e. 2500).
Step-by-step explanation:
We know that sum of an Arithmetic Progression(A.P.) is given by:
where 'n' denotes the "number" of digits whose sum is to be determined, 'a' denotes the first digit of the series and '' denote last digit of the series.
Now the sum of even numbers i.e. 2+4+6+8+....+100 is given by the use of sum of the arithmetic progression since the series is an A.P. with a common difference of 2.
image with explanation
Hence, sum of even numbers from 1 to 100 is 2550.
Also the series of odd numbers is an A.P. with a common difference of 2.
sum of odd numbers from 1 to 100 is given by: 1+3+5+....+99
.
Hence, the sum of all the odd numbers from 1 to 100 is 2500.
Clearly the sum of even numbers from 1 to 100(i.e. 2550) is not double of the sum of odd numbers from 1 to 100(i.e. 2500).
Hence the statement is incorrect.
Step-by-step explanation:
The answer is D. 10. Let me know if you want me to show my work
P=22 rewrite the question as -8+p/11=-6 then move all terms not containing p to the right side p/11=2 multiply both sides of the given equation by 11, the reciprocal, 11*p/11=11*2
Answer:
It will take 5.61 seconds for the coin to reach the stream.
Step-by-step explanation:
The height of the coin, after t seconds, is given by the following equation:
How long will it take the coin to reach the stream?
The stream is the ground level.
So the coin reaches the stream when h(t) = 0.
Multiplying by (-1)
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots 
such that 
, given by the following formulas:
In this question:
So
Time is a positive measure, so we take the positive value.
It will take 5.61 seconds for the coin to reach the stream.
