Stat 3001 practice exam questions





STAT 3001 Practice Exam







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1. An admissions advisor for a generally-known discipline decides he would love to state the medium age of novices at the discipline for some promotional materials. To do this he pulls the registers of 200 vague novices at the discipline.

What mold of con-over is this (notice or illustration), what is the varitalented of concern?


2. Fifty registered nurses are asked how manifold hours they fruit each week. Based on this specimen the appraised medium is 46 hours delay a brink of fallacy of 4.9 hours. Use the absorbed appraises to warrant the faith interim lovely to comprehend the developed population medium.


3. The subjoined histogram represents the movie protractions hit movies in 1998






a How manifold movies completion are represented in this histogram?


b. How manifold movies lasted short than 150 minutes?


c. How manifold movies lasted further than 150 minutes?


d. What is the pristine potential movie protraction represented in this histogram?


4. A legitimate possessions vicar registers the expense of the prospect abodes she has listed at this trice they are as follows:

123,000 155,000 139,000 140,000 159,000 34,000 121,000 and


a. Ascertain the medium and median of the axioms presented

b. Warrant the outlier on the LOW end of the axioms set, displace this appraise and reckon the new medium and median

c. Warrant the outlier on the HIGH end of the axioms set, displace this appraise what is the new medium and median of the axioms set (HINT be firm you put your low appraise tail in!)

5. In a contemplate of 2,150 US teachers it was set-up that 60% of them said if they could begin their sphericals frequently they would cull a opposed spherical. The brink of fallacy was 5 percentage points

What was the sight of this con-over

What is the population

Identify the population parameter of concern

Identify the specimen

What is the raw axioms placid for this con-over

Identify the specimen statistic

Based on the brink of fallacy warrant the concatenate of appraises lovely to comprehend the population parameter of concern

6. The subjoined ttalented shows the medium wprospect and model failure for opposed pretenseed M and M’s in grams



Standard failure










Assume the utensil satisfaction the bag is set to discard M and M’s further than 2 model failures aloft and under the medium

For each pretense ascertain the concatenate of burdens that are accepttalented to the vending utensil





7. The subjoined ttalented measures the wprospect of M and M’s (in grams) of manifold pretenses of the candy.

Oconcatenate Blue Green

0.903 0.838 0.911

0.92 0.875 1.002

0.861 0.87 0.902

1.009 0.956 0.93

0.971 0.968 0.949

0.898 0.89

0.942 0.902



Use a 0.01 resemblingize of sensation to proof the pretension that the opposed pretenses all possess the selfselfidentical medium.

a. Ascertain the p appraise

b. At this resemblingize is there symbolical declaration to say that all pretenses possess the selfselfidentical medium?

8. A statistics novice determined to roll a dice 50 periods, she rolled the reckon two 11 periods. Is the distinction inentire what the novice rolled and what is theoretically expected statistically symbolical?

9. Axioms was chronicled for the reckon of abode runs hit for three baseball players, Mark McGwire, Sammy Sosa and Barry Bonds. The Analysis of Variance results obtained from software are set-up under. The sensation resemblingize is 0.10 in proofing the void fancy.

Source: DF: SS: MS: Proof Stat Precarious F: P-Value:

Treatment: 2 9546.87 4773.43 3.35 2.32 0.036

Error: 206 293224.08 1423.41

Total: 208 302770.95


What is the void fancy?

What is the opinion fancy

What is the p appraise

Is there resembling declaration to influence the pretension that the three players possess opposed medium reckon of abode runs hit?


10. A inquiryer wishes to appraise the medium reckon of hours that exalted discipline novices lavish on facecompass each day. A brink of fallacy of 0.22 hours is desired. Past studies allude-to a population model failure of 2.1 hours is sound, appraise the minimum specimen greatness needed to appraise the population medium delay the desired correctness.


11. A con-over was manufactured inentire 1200 Walden Students. Inentire these novices 700 were Masters of Nursing novices and 520 of these were commencement their pristine online spherical. Inentire the 500 other novices, 410 were commencement their pristine online spherical.

a. What percentage of novices were nursing novices

b. What percentage of nursing novices were commencement their pristine online spherical

c. Inentire those who were NOT nursing novices what percentage were commencement their pristine online spherical?

d. What percentage of the novices were commencement the pristine online spherical?

12. On inquiry con-over of unfair garbage use inentire teenagers shows a decline from 11.4% in 1997 to 9.5% now. Suppose a con-over in a wide exalted discipline reveals that in a single vague specimen of 1054 novices 97 news using unfair garbages. Use the 0.05 sensation resemblingize to proof the principal’s pretension that unfair garbage use is under the generally-known medium.

a. formulate the void and opinion fancy

b. The specimen statistics are the specimen greatness n=1054 and the specimen symmetry , ascertain the specimen symmetry sphericaled to impure decimal places

c. Ascertain the model beak, z for the specimen symmetry

d. Is there resembling declaration to influence the principals pretension that the unfair garbage use at this discipline is under the generally-known medium?

13. Suppose you comprehend the division of specimen symmetrys in specimens of 300 registered toners who earn tone for canvasser A is usual delay a medium of 0.34 delay a model failure of 0.02. Suppose you chosen a vague specimen of 300 toners and ascertain the symmetry of those earning to tone for canvasser A is 0.38.

a. How manifold model failures is the specimen symmetry from the medium of the division of specimen symmetrys?

b. What is the appearance the chosened specimen would possess a symmetry of short than 0.38?

14. You chosen a vague specimen of n=15 families in your vicinity and ascertain the subjoined lineage greatnesss.

















Find the medium lineage greatness from the specimen as well-mannered-mannered as the model failure

What is the best appraise for the medium specimen greatness for the population of all lineage greatnesss in the state?

What is the 95% faith interim for the medium?

Do you affect this specimen is figurative of the perfect race why or why not?


15. Absorbed the subjoined fancy statements:

Ho: The medium GPA of males=medium GPA of females

Ha: The medium GPA of males is not resembling to the medium GPA of females

Explain in the texture of GPA for males and females what it mediums to frame a mold I and mold II fallacy.


16. A single vague specimen of 25 novice IQ beaks is chosened. The medium beak is 102.5 delay a model failure of 12.8. Us the t division to fabricate a 95% faith interim for the population medium.


Solution: Brink of fallacy = t * (s / SQRT n )


S = model failure appraise

SQRT = balance rise symbol

n = specimen greatness

t = 2.064 (for this bearing)


Find the t appraise delay quality of immunity = 25-1 = 24 (or closest to 24 in the t consultation) and alpha 0.05 or 5%.


After you ascertain the brink of fallacy, add and deduct it from the absorbed medium appraise to ascertain the Faith interim.


Confidence interim = medium appraise +/- brink of fallacy appraise





17. Exhibit that the population medium is to be appraised from a specimen. Use the specimen results to approach the brink of fallacy and 95% faith resemblingize.

Sample greatness=121 specimen medium=80 specimen model failure =14

18. A single yes/no contemplate is presented to two groups of subjects, those delay result and those delayout. The results are summarized in the two way ttalented under.




Respondent has result



Respondent does not possess result



a. State the void and opinion hypotheses

b. Ascertain the ttalented of expected frequencies

c. Ascertain the chi balanced proof statistic

d. Ascertain the precarious appraise of the chi balanced proof statistic at a 0.05 resemblingize of sensation

e. Based on these appraises which fancy is influenceed?

19. In a new con-over of 353 4 year old girls the subjoined axioms was placid:


One of the girls proveed 40 pounds, she was heavier than 200 of the other girls. What percentile is this appraise?

One of these girls proveed 24 pounds, she was heavier than 18 of the other girls, what percentile was this detail appraise?

One of the girls proveed 44 pounds and was heavier than 301 of the other girls. What is the percentile of this detail appraise?

20. A exalted discipline novice rolls a dice 12 periods and registers the subjoined results

1 4 6 2 2 3 4 5 6 1 2 3

Based on these results entire the subjoined ttalented (spherical to the direct tenth as needed)



Relative number (as a %)

Cumulative number














21. Exhibit the medium wprospect of 5 year olds is usually arranged delay a medium of 45 pounds and model failure of 5 pounds. Using the 68-96-99.7 administration ascertain the subjoined:

a. Percent of five year olds who prove short than 40 pounds

b. The percent who prove further than 55 pounds

c. The percent who prove inentire 40 and 55 pounds

22. State if the subjoined varitalented is innate or indispensable and afford their resemblingize of measurement. If it is indispensable in structure stat if it is true or discrete.

Number of facecompass friends

Wprospect in pounds

23. The whole of proceeds herd preserve on medium has declined from 7% to 4%.

a. The savings reprimand has declined by ____ percentage points

b. Ascertain the percent fluctuate in savings reprimand


Percent of fluctuate = (new proceeds – ancient proceeds) / ancient proceeds

= (0.04 – 0.07) / 0.07

= 0.03 / 0.07

= 0.4285 = 42.85%


24. Based on axioms from the discipline consultation exhibit SAT beaks are usually arranged delay a medium of 1518 points an d a model failure of 325 points.

a. If a specimen of 100 novices is capturenascertain the medium and model failure of the division of specimen mediums

b. If a specimen of greatness 121 novices is capturen ascertain the medium and model failure of the division of specimen mediums

25. A single vague specimen of 16 opposed cereals is obtained; the sugar gratified (in grams) is measured for each cereal. The specimen has a medium of 0.295 grams, a model failure of 0.168 grams. Use the 0.05 resemblingize of sensation to proof the pretension that the medium whole of sugar is short than 0.3 grams.

a. State the void and opinion fancy statements

b. Ascertain the proof statistic T

c. Which fancy does the axioms influence?

26. A vague specimen of thirty six cans of cola has a medium of 12.19 ounces delay a model failure of 0.11 ounces. Exhibit we are using a 0.05 resemblingize of sensation to proof the fancy the medium can of cola comprehends further than 12.19 ounces. The population medium is 12 ounces.

a. Ascertain the proof statistic z

b. Ascertain the p appraise

27. The subjoined axioms set includes the selling expenses of abodes (in thousands) and the whole of taxes paid

Selling Taxes

142 3167

175 4033

129 1471

138 3204

232 3513

135 3028

150 3131

207 5158


Find the r and r balanced appraises

28. A population medium is to be appraised from the specimen feeling under. Ascertain the brink of fallacy and 95% faith interim.

Sample greatness 100, specimen medium 75.0 specimen model failure 10.0

29. The subjoined ttalented affords the aboderun distances of ten abode runs hit by Sammy Sosa and Mark McGwire. Ascertain the concatenate and model failure for each player

























30. In a Gallup poll targeting 1025 vaguely chosened adult Americans 47% deemd that the races best years were calm?} afront of us (rather than subsequently us). Warrant the subjoined:

a. The specimen

b. The population

c. The sampling course used

d. Warrant the specimen statistic

e. Warrant the population parameter


f. Do you deem the specimen is figurative of the population? Why?