linda,rumi,liz,amy,adam,and sam ran a 800-meter race.Adam BEAT liz by 7meter Sam beat linda by 12 meters. Adam finished 5 meters
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Answer:
We conclude that the sample is from a population of songs with a mean greater than 210 seconds.
Step-by-step explanation:
We are given that a simple random sample of 40 current hit songs results in a mean length of 252.5 seconds.
Assume that the standard deviation of song lengths is 54.5 sec.
Let = <u><em>population mean length of the songs</em></u>
So, Null Hypothesis, :
210 seconds {means that the sample is from a population of songs with a mean smaller than or equal to 210 seconds}
Alternate Hypothesis, :
> 210 seconds {means that the sample is from a population of songs with a mean greater than 210 seconds}
The test statistics that will be used here is <u>One-sample z-test statistics </u>because we know about population standard deviation;
T.S. = ~ N(0,1)
where, = sample mean length of songs = 252.5 seconds
= population standard deviation = 54.5 seconds
n = sample of current hit songs = 40
So, <u><em>the test statistics</em></u> =
= 4.932
The value of z-test statistics is 4.932.
Now, at 0.05 level of significance, the z table gives a critical value of 1.645 for the right-tailed test.
Since the value of our test statistics is more than the critical value of z as 4.932 > 1.645, so <u><em>we have sufficient evidence to reject our null hypothesis</em></u> as it will fall in the rejection region.
Therefore, we conclude that the sample is from a population of songs with a mean greater than 210 seconds.
There are 
ways of selecting two of the six blocks at random. The probability that one of them contains an error is
So
has probability mass function
These are the only two cases since there is only one error known to exist in the code; any two blocks of code chosen at random must either contain the error or not.
The expected value of finding an error is then
So
These are the only two cases since there is only one error known to exist in the code; any two blocks of code chosen at random must either contain the error or not.
The expected value of finding an error is then