a brother is 12 years older than his sister. four years ago, the brother was 3 times as old as the sister is now. how old is the
2 answers:
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<em>Evaluate 1/4c+3d when c=6, and d=7.</em>
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Replace c with 6, and d with 7:-
On simplification,
On further simplification,
On further simplification,
Adding the numerators,
Finally, Reducing the fraction:-
Answer:
The mean of the sampling distribution of x is 0.5 and the standard deviation is 0.083.
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.
For the population, we have that:
Mean = 0.5
Standard deviaiton = 0.289
Sample of 12
By the Central Limit Theorem
Mean = 0.5
Standard deviation
The mean of the sampling distribution of x is 0.5 and the standard deviation is 0.083.