Step-by-step explanation:
450 - 396 = 54
(54/450) * 100% = 12%
Hence the decrease is 12%.
Answer:
Its standard deviation is 3.79.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this problem, we have that:

So

Its standard deviation is 3.79.
Depends on how much space you have on your device
8 would be B.
The ratio is 1:5, so the answer has to be a division of 5.
15*5 does not equal 90, but 18 does.
9 is correct.