Answer:
The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.
Step-by-step explanation:
What is Confidence Interval?
The confidence interval represents an interval that we can guarantee that the target variable will be within this interval for a given confidence level.
The confidence interval is given by

Where
is the mean weight
is the standard deviation
is the critical value from t-table and n is the sample size.
The term
is known as margin of error.
As the sample size is decreased the corresponding margin of error increases which results in wider confidence interval which means smaller precision.
The student who weighted the rock 5 times has a 95% confidence interval of (25.2, 29.1) which is guaranteed to be more wider (less precise) than the other student who weighted the rock 20 times.
We can say with 95% confidence that the true mean weight of the rock is within the interval of (25.2, 29.1).
Answer: The system of equations has NO SOLUTION.
Step-by-step explanation:
The equation of the line in Slope-Intercept form is:

Where "m" is the slope and "b" is the y-intercept.
Given the following system of equations:

Write the first equation and solve for "y" in order to express it in Slope-Intercept form:

You can identify that:

Apply the same procedure with the second equation. Then:

You can identify that:

The slopes of both lines are equal, therefore the lines are parallel and the system has NO SOLUTION.