Answer:
Yes
Step-by-step explanation:
Given that your classmate suggests that the margin of error in the interval could be reduced if the confidence level were changed to 90% instead of 95%.
This is a true statement
Reason:
Confidence interval = mean±margin of error
margin of error = Critical value * Std error
Thus we have the higher the margin of error the wider the confidence interval.
And the higher the critical value the higher the margin of error.
In other words when confidence level is reduced from 95% to 90% we get reduced critical value and as a result narrower confidence interval.
True statement
Answer:
Step-by-step explanation:
We can use the quadratic formula or factor, This looks hard to factor so we should use the quadratic formula.
ax^2 + bx + c
so
a=4
b=-9
c=2
you can try it by hand or use this:
https://www.calculatorsoup.com/calculators/algebra/quadratic-formula-calculator.php
you get x=2 and x=0.25 these are the x intercepts (where Y is zero and where the graph crosses the x axis)
so mark x=2 and x=0.25 with a dot on a number line and you can draw a straight line between them since that is the part of the graph that is below the x axis (because the equation has <0) it is a positive parabola because the "a" value is positive and the presence of a "b" value means part of the graph will be below the x axis
