Question 1

A poll was taken of a random sample of 1189 college students. Of these students, 789 reported that they had a drinking binge (more than 10 drinks in an evening) in the past month. Select the most believable conclusion.

Accepted Answer

The poll was taken of a random sample of 1189 college students, and 789 reported that they had a drinking binge in the past month. So, about 65% of college students indulged in binge drinking last month.

Question 2

Avogadro's number is the number of molecules of a substance in a quantity of the substance measured in grams equal to its atomic weight. It can only be determined by chemistry or physics experiments. It is named after Amadeo Avogadro, who postulated in 1811 that this number was the same for all substances. Various values for this constant have been determined experimentally. Some of them are $ 6.02 \times 10^{23}, 6.022 \times 10^{23} $, and $ 6.02214199 \times $ $ 10^{23} $. The $ 10^{23} $ means that you have to move the decimal point 23 places to the right. Which of these values is the most accurate?

Accepted Answer

The answer of Avogadro's number is the number of molecules...

Question 3

A part of the CPI table is given below: $$\begin{array} { l | l | l | l | l | l } 
\text { Year } & 1975 & 1980 & 1985 & 1990 & 1995 \
\hline \text { CPI } & 53.8 & 82.4 & 107.6 & 130.7 & 152.4
\end{array}$$ What is the percent increase of a market basket of goods from 1975 to 1985? Round the percent to the nearest integer.

Accepted Answer

The answer of A part of the CPI table is...

Question 4

A professor's checking account balance a year ago was $1470. Currently, it is $1040. Calculate the relative percentage change to the nearest percentage point.

Accepted Answer

The relative percentage change is calculated as ((New Value - Old Value) / Old Value) * 100. Here, ((1040 - 1470) / 1470) * 100 = (-430 / 1470) * 100 ≈ -29%.

Question 5

Convert 0.0195% to decimal form.

Accepted Answer

To convert a percentage to a decimal, divide by 100. So, 0.0195% becomes 0.0195 / 100 = 0.000195.

Question 6

Research shows that 15.5% of persons 20-25 years old vote and 63.5% of persons 60-65 years old vote. What is the relative change from the younger group to the older group, to the nearest percent?

Accepted Answer

The relative change is calculated as ((63.5 - 15.5) / 15.5) * 100%, which equals 310%.

Question 7

Suppose that the cost of a statistics text was $60 in 1985 and is $90 in 2010. What is the 'Statistics Text Index' number, rounded to the nearest tenth, for the 2010 edition with the 1985 price as the reference value?

Accepted Answer

The Statistics Text Index number is calculated as (New Price / Old Price) * 100. In this case, the new price is $90 and the old price is $60, so the index number is (90 / 60) * 100 = 150.

Question 8

The number of textbooks owned by a student

Accepted Answer

The number of textbooks is a quantitative variable because it represents a countable quantity.

Question 9

Identify the number as either continuous or discrete
-The voltage of the electricity in a power line

Accepted Answer

Voltage is a continuous variable because it can take on any value within a given range, including fractions and decimals.

Question 10

Which of the following statements is correct?

Accepted Answer

Precision refers to the consistency of measurements, while accuracy refers to how close a measurement is to the true value. A precise measurement can be consistently off from the true value, hence not necessarily accurate.

Question 11

The approximate value of π is 3.1415927. Which of the following experimentally determined values is the most accurate?

Accepted Answer

3.14 is the closest approximation to the true value of π (3.1415927) among the given options.

Question 12

Select the description that most completely classifies the given variable
-A Prostate Specific Antigen (PSA) test is useful in detecting prostate cancer in men. A sample of blood is analyzed and the concentration of PSA is reported in nanograms per milliliter. Values less than 4.0 are considered normal and values over 10.0 indicate that further tests are needed. The best classification of the PSA variable is

Accepted Answer

The PSA test measures the concentration of PSA in the blood, which is a numerical value that can take any value within a range, making it a quantitative, continuous variable.

Question 13

Convert 1779% to decimal form.

Accepted Answer

The answer of Convert 1779% to decimal form.
...

Question 14

Identify the number as either continuous or discrete
-The number of DIRECT TV customers

Accepted Answer

The number of DIRECT TV customers is discrete because it represents a countable quantity, which can only take whole number values.

Question 15

A golfer estimates that the distance to the hole for his next shot is 200 yards. The actual distance is exactly 212 yards. What is the relative error?

Accepted Answer

Relative error is calculated as (estimated value - actual value) / actual value. Here, it is (200 - 212) / 212 = -12 / 212 = -0.0566, which is approximately -5.7%.

Question 16

A recipe for grape jelly calls for 4 pounds of grapes. The jelly maker estimates the 4 pounds of grapes by standing on a bathroom scale with and without the grapes. The scale only shows the weight to the nearest pound. Identify the error in the weight as systematic or random.

Accepted Answer

The error is random because the scale rounds the weight to the nearest pound, introducing variability in the measurement each time.

Question 17

Select the statement for which a ratio of the measurements is meaningful. State "Neither" or "Both" if appropriate.
-1 - Jan earned a B on her test and Bob earned a C. 
2 - Bob wears size 9 shoes and Earl wears size 13.

Accepted Answer

The answer of Select the statement for which a ratio...

Question 18

A player's number on her soccer jersey

Accepted Answer

A player's number on her soccer jersey is qualitative because it is used to identify or categorize the player, not to measure or quantify anything.

Question 19

The grape jelly maker in the previous problem actually uses 3 pounds, 12 ounces of grapes instead of the 4 pounds called for by the recipe. What is the relative error? (There are 16 Ounces in a pound.)

Accepted Answer

The relative error is calculated by taking the difference between the actual amount used and the amount called for by the recipe, divided by the amount called for by the recipe. The actual amount used is 3 pounds 12 ounces, which is 60 ounces. The recipe calls for 4 pounds, which is 64 ounces. The difference is -4 ounces. The relative error is (-4/64) * 100% = -6.25%.

Question 20

Amtrak passenger trains are often late in arriving at their destinations. Identify the potential error in arrival time as systematic or random.

Accepted Answer

The answer of Amtrak passenger trains are often late in...

Quiz 2: Measurement in Statistics