Practice Test 1

Determine whether the given value is a statistic or a parameter. A health and fitness club surveys 40 randomly selected members and found that the average weight of those questioned is 157 lb.

Statistic

Determine whether the given value is a statistic or a parameter. A sample of 120 employees of a company is selected, and the average age is found to be 37 years.

Statistic

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) 49, 34, and 48 students are selected from the Sophomore, Junior and Senior classes with 496, 648, and 481 students respectively.

Stratified

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of age.

Stratified

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) A market researcher selects 500 people from each of 10 cities.

Stratified

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) A sample consists of every 49th student from a group of 496 students.

Systematic

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) A tax auditor selects every 1000th income tax return that is received.

Systematic

An electronics store receives a shipment of 8 boxes of calculators. Each box contains 10 calculators. A quality control inspector chooses a box by putting 8 identical slips of paper numbered 1-8 into a hat - mixing thoroughly and then picking a slip at random. He then chooses a calculator at random from the box selected using a similar method with 10 slips of paper in a hat. He repeats the process until he obtains a sample of 5 calculators for quality control testing. Does this sampling plan result in a Random Sample? Simple Random Sample? Explain.

The sample is RANDOM because all calculators have the same chance of being chosen. It is also a Simple Random Sample because all samples of 5 calculators have the same chance of being chosen.

A computer company employs 100 engineers and 100 hardware engineers. The personnel manager randomly selects 20 of the software engineers and 20 of the hardware engineers and questions them about career opportunities within the company. Does this sampling plan result in a Random Sample? Simple Random Sample? Explain.

The sample is RANDOM because all employees have the same chance of being selected. It is NOT a simple random sample because some samples are not possible (such as 30 software engineers and 10 hardware engineers).

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Amount of fat (in grams) in cookies

Ratio

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Salaries of college professors.

Ratio

The following data represents a selection of performance IQ sores from 22 children: 78, 97, 107, 80, 90, 83, 101, 121, 108, 100, 110, 111, 97, 51, 94, 80, 101, 92, 100, 77, 108, 85 Find the lower class limit and class width. Then create a frequency distribution.

Class width = 121 - 51 / 6 = 11.6 (round up) = 12. IQ Scores Frequency 51 - 62 1 63 - 74 0 75 - 86 6 87 - 98 5 99 - 110 8 111 - 122 2

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) An education researcher randomly selects 48 middle schools and interviews all the teachers at each school.

Cluster

Determine whether the given value is a statistic or a parameter. After inspecting all of 55,000 kg of meat stored at the Wurst Sausage Company, it was found that 45,000 kg of the meat was spoiled

Parameter

Determine whether the given value is a statistic or a parameter. After taking the first exam, 15 of the students dropped the class.

Parameter

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers.

Random

Determine whether the given value is from a discrete or continous data. The height of a 2 year old maple tree is 28.3 ft.

Continous

Determine whether the given value is from a discrete or continous data. The temperature of a cup of coffee is 67.3 °F

Continous

Determine whether the given value is from a discrete or continous data. The weight of Bill's pack as he sets off on a backpacking trip is 48.3 lbs.

Continous

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) A researcher interviews 19 work colleagues who work in his building.

Convenience

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) To avoid working late, a quality control analyst only inspects the first 100 items produced in a day.

Convenience

Identify which of these sampling is used: (random, stratified, systematic, cluster, convenience) The name of each contestant is written on a separate card, the cards are placed in a bag, and 3 names are picked from the bag.

Random

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Ages of survey respondents

Ratio

Determine whether the given value is from a discrete or continous data. The number of freshmen entering college in a certain year is 621.

Discrete

Determine whether the given value is from a discrete or continous data. The number of limbs on a 2 year old oak tree is 21.

Discrete

Determine whether the given value is from a discrete or continous data. The number of phone calls a sales representative makes in a month is 425.

Discrete

Determine whether the given value is from a discrete or continous data. The number of stories in a Manhattan building is 22.

Discrete

Create a relative frequency distribution and a cumulative frequency distribution for the IQ scores.

IQ Scores Rel. Freq. Cum.Freq. 51 - 62 4.5% 1 63 - 74 0.0% 1 75 - 86 27.3% 7 87 - 98 22.7% 12 99 - 110 36.4% 20 111 - 122 9.1% 22

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Temperatures of the ocean at various depths.

Interval

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) The temperatures of 8 different plastic spheres.

Interval

Does the histogram for the IQ scores a describe a normal distribution? Why or why not?

It is approximately normal. There is a (kind-of) bell shape and the bars are somewhat symmetric.

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Nationalities of survey respondents.

Nominal

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) The subjects in which college students major.

Nominal

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Student's grades, A, B,C on a test

Ordinal

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) Survey responses of "good, better, best"

Ordinal

Determine which of the following measurements is most appropiate (nominal, ordinal, interval, ratio) The sample of spheres categorized from sofest to hardest.

Ordinal