Of interest is to determine the mean age of students at the time they take the comprehensive exam for all students enrolled in g
1 answer:
Answer:
The 98% confidence interval for the mean age of students at the time they take the comprehensive exam for all students enrolled in graduate programs that require students to take comprehensive exams is between 26.2 and 28.8 years. This means that we are 98% sure that the mean age of all students taking the exam is between 26.2 and 28.8 years.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 31 - 1 = 30
98% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 30 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.457
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 27.5 - 1.3 = 26.2 years
The upper end of the interval is the sample mean added to M. So it is 27.5 + 1.3 = 28.8 years
The 98% confidence interval for the mean age of students at the time they take the comprehensive exam for all students enrolled in graduate programs that require students to take comprehensive exams is between 26.2 and 28.8 years. This means that we are 98% sure that the mean age of all students taking the exam is between 26.2 and 28.8 years.
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A square has 4 equal sides, which means when you need to work out the area, you're doing length × width, but the length and width are exactly the same, because it's a square (look at the picture if you don't understand this).
That means you just have to pick any side (let's call this side x), and multiply it by another side of the square. Now, because all of the sides are equal, you're doing x multiplied by x, which is the same as x².
Therefore, if the area is equal to x², and in this question, it's also equal to 49 (as stated in the question), we can equate them to each other:
x² = 49
Now to get the x by itself, we need to do the opposite of squaring, which is square rooting. Therefore, we square root both sides of the equation:
√x² = √49
The √ and the ² cancel out, so you're just left with x:
x = √49
The square root of 49 is just 7, so we can replace √49 with 7, and we get:
x = 7
Now remember, earlier, I called x the value of one side. Therefore, by remembering that, you know that the value of one side is equal to 7. And because all the sides are the same as each other, each side is equal to 7 metres.
Therefore, your final answer is 7 metres :)
