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:
Option B.
Step-by-step explanation:
Let the radius of the snare drum = r
and radius of the model = R
Ratio of the dimensions of the snare drum and the model = 1 : 4
So, 
Now as per question, dimensions of the snare drum is multiplied by a scale factor of 
Radius of the snare drum = 
Ratio of the radius of the snare drum and cylindrical model ,
Therefore, the cylinder with Sara's dimensions will be geometrically similar but the scale factor will be 1 : 2
Option B is the answer.
There are 6 children that ate 9 cookies what is the ratio of the children and cookies?
Hope this helps!
75/3000=x/4000
times both sides by 1000
75/3=x/4
times both sides by 4
300/3=x
100=x
answer is 100 hours
