Harper MTH165 Homework Section 8.1 Latest 2020 MAY

MTH165 ELEMENTARY STATISTICS

Homework Section 8.1

In this section you learned about another branch of inferential statistics:  confidence intervals

What is the definition of a point estimate?

                For qualitative data, we use ____ as a point estimate for ____

                For quantitative data, we use ___ as a point estimate for ___

                What is the definition of an interval estimate? An interval of numbers around the point estimate that we will have a certain level._____________________________________________

                Draw a picture of how the point estimate, margin of error and interval estimate are all related.

                A higher level of confidence makes a (wider/narrower) interval.

                A larger sample size makes the width of the interval (wider/narrower/stay the same).

Fill in the following as you work through your given problems in MyOpenMath

1.            If the sample size (increases/decreases) from _____ to ______, the confidence interval will …

2.            If the confidence level (increases/decreases) from _____ to ______, the confidence interval will …

3.            If the confidence level (increases/decreases) from _____ to ______, the confidence interval will …

4.            If the sample size (increases/decreases) from _____ to ______, the confidence interval will …

5.            a.            individual object:  ___ high school basketball player___________________________________________

                b.            Variable information collected from each object: _____height______________________________

What type of variable is this?  quantitative-discrete                         quantitative-continuous                               qualitative

                c.             Given:  95% confidence interval for μ__:     (    8        ,  26           )

Interpret in context:  We are 95% confident that the mean height of all high school basketball players is/are between 8 inches and 26 inches

d.            What is the value of the point estimate for μ?  _ __ = __ _______ __inches____ (symbol, value, units)

                e.            What is the margin of error associated with this interval?  ME = ____________ ________

f.             Draw a picture that shows the relation between the point estimate, the interval estimate and the

                margin of error.

6.            a.            individual object:  Harper statistics student______________________________________________

                b.            Variable information collected from each object: final exam score___________________________________

What type of variable is this?  quantitative-discrete                         quantitative-continuous                               qualitative

                c.             Given:  95% confidence interval for _ μ_:     (    149        ,  160           )points

                                Interpret in context:  We are 95% confident that the mean final exam score of all harper statistics student is/are between 149  points and  160 points.____________________________________________________________

                _______________________________________________________________________________

                d.            What is the value of the point estimate for μ?  X ?= _________ _points_____ (symbol, value, units)

                e.            What is the margin of error associated with this interval?  ME = ________ ___points _________ ________

f.             Draw a picture that shows the relation between the point estimate, the interval estimate and the

                margin of error.

7.            a.            individual object:  high school basketball player ______________________________________________

                b.            Variable information collected from each object: played basketball in college ___________________________________

                                What type of variable is this?  quantitative-discrete                         quantitative-continuous                               qualitative

                c.             Given:  95% confidence interval for _ p _:     (   68%         ,  72%           )

                                Interpret in context:  We are 95% confident that the percentage of all high school basketball players that played basketball in college is between 68% and 72%____________________________________________________________

                d.            What is the value of the point estimate for μ?  ___ = _______ ___%___  (symbol, value, units)

                e.            What is the margin of error associated with this interval?  ME = __________ ___% _____

f.             Draw a picture that shows the relation between the point estimate, the interval estimate and the

8.            a.            individual object:  incoming student______________________________________________

                b.            Variable information collected from each object: whether or not they are left handed___________________________________

What type of variable is this?  quantitative-discrete                         quantitative-continuous                               qualitative

                c.             Given:  95% confidence interval for _

p_:     (     9.3%       ,   11%          )

                                Interpret in context:  We are 95% confident that the percentage of all incoming students that are left-handed is between 9.3% and 11%

                d.            What is the value of the point estimate for μ?  _p ?___ = __________ ___%___ (symbol, value, units)

                e.            What is the margin of error associated with this interval?  ME = ___________ __%______

f.             Draw a picture that shows the relation between the point estimate, the interval estimate and the