How does a chicken kill a wolf?
1 answer:
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Let the smaller number be x.
Given, the larger number is 7 times the smaller number.
So, the larger number = 7x.
Given, 3 times the larger number is 7 more than 4 times the smaller number.
So we can write the equation as,
Now we have to move 4x to the left side by subtracting 4x from both sides.
To get x, we will divide both sides by 17. We will get,
So the smaller number =
The larger number = =
So we have got the required numbers.
Smaller number = and larger number =
.
Answer:
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution 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 = 25 - 1 = 24
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.064
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 81.5 - 4.21 = 77.29
The upper end of the interval is the sample mean added to M. So it is 81.5 + 4.21 = 85.71.
The 90% confidence interval for the mean test score is between 77.29 and 85.71.