Answer:
a)
With:
b)
c)
d)
Step-by-step explanation:
For this case we know the following propoertis for the random variable X
We select a sample size of n = 81
Part a
Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:
With:
Part b
We want this probability:
We can use the z score formula given by:
And if we find the z score for 89 we got:
Part c
We can use the z score formula given by:
And if we find the z score for 75.65 we got:
Part d
We want this probability:
We find the z scores:
87.5% of 32 questions = 28 questions.
32 - 28 = 4
so there are 4 questions to be done after dinner.
Answer:
5-1.6n
Step-by-step explanation:
5+3.2n-4.8n=5-1.6n
The answer is (, )=(6−2, )
The equation you need to find x is,
.
Then solving for x gives you .
Hope this helps.