Statistics, Data Analysis, and Probability Flashcards

Which sampling method involves randomly selecting participants from a complete list of the entire population?

Answer: Simple random sampling

Simple random sampling gives every member of the population an equal chance of being selected from the complete list.

A data set contains the values 2, 5, 5, 6, 7, 8, 50. Which measure of central tendency would be most misleading when summarizing this data?

Answer: Mean

The outlier 50 dramatically pulls the mean upward, making it unrepresentative of the rest of the data.

A two-way frequency table shows data on gender and preference for a school mascot. There are 80 students total. If 40 are boys and 25 boys prefer the eagle mascot, what fraction of boys prefer the eagle?

Answer: 5/8

25 out of 40 boys prefer the eagle: 25/40 = 5/8.

A histogram displays test scores in intervals of 10. The bar for 70–79 has a frequency of 15, and the bar for 80–89 has a frequency of 20. What is the total number of students who scored between 70 and 89?

Answer: 35

Add the frequencies for both intervals: 15 + 20 = 35 students total.

A student rolls a standard 6-sided die. What is the probability of rolling a number greater than 4?

Answer: 1/3

Numbers greater than 4 on a die are 5 and 6 — that is 2 out of 6 outcomes, which simplifies to 1/3.

Which statement best describes a data set with a large standard deviation?

Answer: The data values are widely spread out from the mean

A large standard deviation indicates that the data values are spread far from the mean, showing high variability.

A store tracks daily sales for a week: $200, $250, $300, $250, $400, $350, $250. What is the mode of the sales data?

Answer: $250

$250 appears three times, more than any other value, making it the mode.