which measure for the center of a small sample set would be most affected by outliers

ATI TEAS 7

TEAS Test Math Prep

1. Which measure for the center of a small sample set would be most affected by outliers?

A. Mean
B. Median
C. Mode
D. None of the above

Correct answer: A

Rationale: The mean is calculated by summing all values in a dataset and then dividing by the total number of values. Outliers, which are data points significantly different from the other values, can greatly impact the mean because they affect the sum. The mean is sensitive to extreme values, making it the measure for the center of a small sample set most affected by outliers. The median, on the other hand, is not influenced by outliers as it represents the middle value when the data points are ordered. The mode is the value that appears most frequently in the dataset and is not directly influenced by outliers. Therefore, the correct answer is the mean, as it is highly influenced by outliers in a small sample set.

2. How do you convert Fahrenheit to Celsius and Celsius to Fahrenheit?

A. Fahrenheit to Celsius: Subtract 32, then divide by 1.8; Celsius to Fahrenheit: Multiply by 1.8, then add 32
B. Fahrenheit to Celsius: Subtract 32, then divide by 2; Celsius to Fahrenheit: Multiply by 1.8, then add 20
C. Fahrenheit to Celsius: Multiply by 2, then add 32; Celsius to Fahrenheit: Subtract 32, then divide by 1.8
D. Fahrenheit to Celsius: Subtract 30, then divide by 1.8; Celsius to Fahrenheit: Multiply by 2, then add 32

Correct answer: A

Rationale: To convert Fahrenheit to Celsius, you start by subtracting 32 from the Fahrenheit temperature and then divide the result by 1.8. This formula accounts for the freezing point of water at 32°F and the conversion factor to Celsius. To convert Celsius to Fahrenheit, you multiply the Celsius temperature by 1.8 and then add 32. This process takes into consideration the conversion factor from Celsius to Fahrenheit and the freezing point of water. Choice B is incorrect as dividing by 2 instead of 1.8 would yield an inaccurate conversion. Choice C is incorrect as it involves incorrect operations for both conversions. Choice D is incorrect as subtracting 30 instead of 32 for Fahrenheit to Celsius and multiplying by 2 instead of 1.8 for Celsius to Fahrenheit would provide incorrect results.

3. Sally wants to buy a used truck for her delivery business. Truck A is priced at $450 and gets 25 miles per gallon. Truck B costs $650 and gets 35 miles per gallon. If gasoline costs $4 per gallon, how many miles must Sally drive to make truck B the better buy?

A. 500
B. 7500
C. 1750
D. 4375

Correct answer: D

Rationale: To determine the breakeven point where Truck B becomes the better buy, we need to compare the total costs for both trucks. For Truck A: Total cost = $450 + (miles / 25) * $4. For Truck B: Total cost = $650 + (miles / 35) * $4. To find the point where Truck B is the better buy, set the two total cost equations equal to each other and solve for miles. By solving this equation, we find that Sally must drive 4375 miles for Truck B to be the better buy. Choice A (500) is too low, Choice B (7500) is too high, and Choice C (1750) does not represent the breakeven point where Truck B becomes more cost-effective.

4. What is 1.25 as a fraction?

A. 1 1/4
B. 5/4
C. 4/5
D. 25/20

Correct answer: B

Rationale: To convert a decimal to a fraction, we note that 1.25 can be expressed as 1 + 0.25. Since 0.25 is equivalent to 25/100 or 1/4, we add 1 whole to 1/4 to get 1 1/4, which simplifies to 5/4. Therefore, 1.25 as a fraction is 5/4. Choice A (1 1/4) is the mixed number form of 5/4. Choice C (4/5) and Choice D (25/20) are incorrect fractions that do not represent 1.25.