Answer:
Cheap; Bad
Step-by-step explanation:
According to the experience in the real world.
The standard deviation of what? Percentiles from any normal distribution look the same, just like the unit normal, so you can't really determine the standard deviation of the original scores. You can determine a z score from a percentile. That tells us the number of standard deviations, positive or negative, a given score is away from the mean score. It's a normalized test result.
Your percentile is (a hundred times) the probability that another score is less than your score. We have a normal distribution, so that probability is the integral of the standard normal from negative infinity to our normalized score.
Let's call the percentile rank
, already scaled between zero and 1.
corresponds to a z score
because the fiftieth percentile means we got an exactly average score, 0 standard deviations away from the mean.
We know 68% of the probability will be between -1 and +1 standard deviation. So
corresponds to
and
corresponds to
Similarly, 95% of the probability will be between -2 and +2 standard deviations. So
corresponds to
and
corresponds to
That's about the list I can do off the top of my head. I think three standard deviations is 99.7%. For the rest we just consult a z table or integrated normal table. We find p in the body of the table (maybe |.5-p| depending on the table) and then the column headings tell us our z score.
In this modern age, your computer can do this for you quickly
Answer:
3 seconds.
Step-by-step explanation:
First calculate the time for each 20m length to pass through the bridge.
The train takes 3600 seconds to travel 144,000 m
So it takes 3600/144000 seconds to travel 1m.
and 3600 * 20 / 144000 seconds to travel 20 m.
As the train is 120 m long and there are 6 * 20 m in 120m the answer is:
3600 * 20 * 6 / 144000 seconds.
= 3 seconds.
Answer:
i have no idea. But i will answer because i'm still learning.
Step-by-step explanation:
-2 (3a – 2) = 1/3(7 – 3a)
is whats the question
ok its i'm guessing -2 (3a – 2) = 1/3(7 – 3a)
-2.15384615385
Hope this helps ;)