Can someone please help me with this!!!
1 answer:
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Using the <em>normal distribution and the central limit theorem</em>, it is found that the power of the test is of 0.9992 = 99.92%.
<h3>Normal Probability Distribution</h3>In a normal distribution with mean and standard deviation
, the z-score of a measure X is given by:
- It measures how many standard deviations the measure is from the mean.
- After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.
- By the Central Limit Theorem, the sampling distribution of sample means of size n has standard deviation
.
In this problem:
- The mean is
.
- The standard deviation is
.
- A sample of 30 is taken, hence
.
The power of the test is given by the probability of a sample mean above 8, which is <u>1 subtracted by the p-value of Z when X = 8</u>, so:
By the Central Limit Theorem:
has a p-value of 0.0008.
1 - 0.0008 = 0.9992.
The power of the test is of 0.9992 = 99.92%.
To learn more about the <em>normal distribution and the central limit theorem</em>, you can check brainly.com/question/24663213
Answer:
8 vans
7 buses
Step-by-step explanation:
Let there be "b" buses
and "v" vans
Since 7 people is the capacity of vans, the total capacity is
7v
Also, since 25 people is the capacity of 1 bus, the total capacity is
25b
In total 231 people, so we can write our first equation as:
7v + 25b = 231
Now, we know there are 15 vehicles (bus + vans) in total, so we can write our 2nd equation as:
v + b = 15
Now, we solve for v and b. Let's solve the 2nd equation for v and substitute that into 1st and solve for b first:
v + b = 15
v = 15 - b
Now,
Hence, there are 7 buses
Since 15 vehicles in total, the number of vans is:
15 - 7 = 8 vans
So,
8 vans
7 buses