18. if someone added the number 20 to the set of numbers {1, 2, 4, 5, 12}, would that increase or decrease…
18. if someone added the number 20 to the set of numbers {1, 2, 4, 5, 12}, would that increase or decrease the standard deviation of the set?\n19. which of these approaches would give the best indication of how a particular town is planning on voting on an issue in an election?\na. interviewing 100 political activists in the town as to their predictions.\nb. taking a phone survey of 500 randomly selected likely voters.\nc. having 500 pedestrians in the main city park complete a survey.\n20. the box plot below summarizes 15 data values.\nwhat is the median of the data set?
Answer
18.
Explanation:
Step1: Recall standard - deviation concept
Standard deviation measures the spread of data.
Step2: Analyze the new data point
The original set is {1, 2, 4, 5, 12}. The number 20 is far from the other values. Adding it will increase the spread of the data.
Answer:
Increase
19.
Brief Explanations:
A phone - survey of 500 randomly selected likely voters (Option B) is most representative as political activists (Option A) may have a bias, and pedestrians in a park (Option C) may not be a representative sample of all voters.
Answer:
B. Taking a phone survey of 500 randomly selected likely voters.
20.
Explanation:
Step1: Recall box - plot properties
In a box - plot, the vertical line inside the box represents the median.
Step2: Identify the median value
From the box - plot, the vertical line inside the box is at 7.
Answer:
7