NTN Data Analytics 3

Question 1

A police department's crime mapping software shows that burglaries cluster in three hotspots. What analytical technique is being used?

Accepted Answer

Spatial analysis

Answer

Spatial analysis examines geographic patterns and relationships in data. Crime mapping that identifies hotspot clusters is a classic example of spatial analysis used in law enforcement.

Question 2

An emergency dispatch center processes calls with the following priority levels: Priority 1 (life-threatening) averages 2 minutes handling time, Priority 2 (urgent) averages 5 minutes, and Priority 3 (non-urgent) averages 8 minutes. If daily call volume is 40% Priority 1, 35% Priority 2, and 25% Priority 3, what is the weighted average handling time per call?

Accepted Answer

4.55 minutes

Answer

Weighted average = (0.40 × 2) + (0.35 × 5) + (0.25 × 8) = 0.8 + 1.75 + 2.0 = 4.55 minutes.

Question 3

Which of the following best describes a Type I error in the context of a public safety study?

Accepted Answer

Concluding that a community policing program reduced crime when it actually had no effect

Answer

A Type I error (false positive) occurs when the null hypothesis is incorrectly rejected — concluding there is an effect when none exists, such as claiming a program reduced crime when it did not.

Question 4

A 911 center tracked call volumes over 24 hours and found the data follows a normal distribution with a mean of 45 calls per hour and a standard deviation of 8. Approximately what percentage of hours will have between 37 and 53 calls?

Accepted Answer

68%

Answer

In a normal distribution, approximately 68% of data falls within one standard deviation of the mean. 45 - 8 = 37 and 45 + 8 = 53, which represents ±1 standard deviation.

Question 5

A department collected response time data for 200 incidents. The five-number summary is: minimum 3.1 min, Q1 5.2 min, median 6.8 min, Q3 9.4 min, maximum 22.5 min. Which value is most likely an outlier?

Accepted Answer

22.5 minutes

Answer

Using the IQR method: IQR = Q3 - Q1 = 9.4 - 5.2 = 4.2. The upper fence is Q3 + 1.5 × IQR = 9.4 + 6.3 = 15.7. Since 22.5 exceeds 15.7, it is an outlier.

NTN - National Testing Network Practice Test

NTN - National Testing Network Practice Test

NTN Data Analytics 3