Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be.
</em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.
Answer:

they're all like terms so we just add and subtract
The equation we will use here is A^2+B^2=C^2, which is also know as the Pythagorean Theorem.
The given values are 6 and 9, where they can represent any value, there true values in the equation would be 36(6), and 81(9), so you must select a value that makes the equation true, given the constraints.
with that being said 3, doesnt work because
·36(6)+9(3)≠81(9)
·9(3)+81(9)≠36(6)
·36(6)+81(9)≠9(3)
10 doesnt work either because
·36(6)+81(9)≠100(10)
·81(9)+100(10)≠36(6)
·100(10)+36(6)≠81(9)
12 doesnt work either because
·144(12)+36(6)≠81(9)
·36(6)+81(6)≠144(12)
·81(9)+144(12)≠36(6)
If you see where this is going you would know that there is no valid solution here, however rounding is always a possibility, when you actually do the math 81(9)+36(6)=117, and when squared you get your answer of 10.8, and the closest answer is 10, there fore your answer would be 10
-I hope this is the answer you are looking for, feel free to post your questions on brainly at any time.
Answer:
B
Step-by-step explanation:
Answer:
C. The standard deviation of the sample mean will be smaller than the population standard deviation.
Step-by-step explanation: Standard deviation is described as the square root variance,it is a Mathematical and statistical analysis tool used to understand the variation of treatments or values around the Mean.
The higher the Population the more the chances for deviation from the Mean, samples are always less than the entire population so the chances for variations will be less with sample than with the population.