A natural history museum surveyed the people visiting the museum for one month and created a circle graph to show the age of the
1 answer:
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Answer:
0.025
Step-by-step explanation:
Hello!
Given that the classes are uniformly distributed between 45.0 and 55.0 minutes, the propability distribution will be:
Now, we are looking for a probability P(51.5<x<51.75) which can be computed as:
Therefore:
P(51.5<x<51.75) = 0.025
or
P(51.5<x<51.75) = 2.5%
<em><u>I strongly believe that the answer for both questions have the same answer, I believe this because there is no additional info for a given class or selecting a class. I think both probabilities are the same.</u></em>
Answer:
Step-by-step explanation:
Given that a statistician selected a random sample of 125 observations from a population with a known standard deviation equal to 16 and computed a sample mean equal to 77
We can use Z critical values since population std deviation is known. Also sample size >30
We find std error of mean =
Margin of error = Z critical value * 1.4311
Z critical values for 93% = 1.81
for 89% = 1.60
n Std error Z critical Conf interval
89%
125 1.4311 1.6 (74.71024 79.28976 )
93%
1.81 (74.409709 79.590291 )
We find that when confidence level increases interval width increses.
c) When sigma changes to 441, std error changes to
So we get
n Std error Z critical Conf interval
89%
441 0.7619 1.6 (75.781 78.219 )
93%
1.81 (75.621 78.37904)
d) When n = 625, std error changes to 16/25 = 0.64
n Std error Z critical Conf interval
89%
441 0.64 1.6 (75.976 78.024 )
93%
1.81 (75.842 78.1584)
When sample size increases, confidence interval width decreases.