Answer: (110.22, 125.78)
Step-by-step explanation:
The confidence interval for the population mean is given by :-

Given : Sample size = 463


Significance level : 
Critical value : 
We assume that the population is normally distributed.
Now, the 90% confidence interval for the population mean will be :-

Hence, 99% confidence interval for the mean study time of all first-year students = (110.22, 125.78)
Answer:
D
Step-by-step explanation:
<h2>
Answer:</h2>
This is impossible to solve.
<h2>
Step-by-step explanation:</h2>
For an equation or inequality to be solvable, there must be the same number of inequalities as variables. Here, there is an x and there is a y. This means that you need at least two inequalities to solve it.
You can, however, rearrange to get x or y on one side.
This can be done for x:
5x < 10 + 2y
x < 2 + 2/5y
Or it can be done for y:
5x < 10 + 2y
5x - 10 < 2y
2.5x - 5 < y
Answer:
Step-by-step explanation:
Given that a professor sets a standard examination at the end of each semester for all sections of a course. The variance of the scores on this test is typically very close to 300.

(Two tailed test for variance )
Sample variance =480
We can use chi square test for testing of hypothesis
Test statistic = 
p value = 0.0100
Since p <0.05 our significance level, we reject H0.
The sample variance cannot be claimed as equal to 300.
Using the given information, the value of Σfd is 800
<h3>Calculating mean using Assumed mean </h3>
From the question, we are to determine the value of Σfd
The formula for mean, using the assumed mean method is given by

Where
is the mean
A is the assumed mean
From the given information,



Putting the parameters into the equation, we get





Hence, the value of Σfd is 800
Learn more on Mean here: brainly.com/question/20118982
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