ATDH - Admission Test for Dental Hygiene Data and Probability Analysis Questions and Answers — Questions and Answers
Question 1: A dental hygienist measures six periodontal pocket depths around a specific molar, recording the following values in millimeters: 3, 2, 4, 5, 3, 1. What is the mean (average) pocket depth for this tooth?
- 3.5 mm
- 18 mm
- 3 mm (Correct answer)
- 4 mm
Correct answer: 3 mm
The mean is calculated by summing all the measurements and dividing by the number of measurements. The sum is 3 + 2 + 4 + 5 + 3 + 1 = 18 mm. There are 6 measurements, so the mean is 18 mm / 6 = 3 mm.
Question 2: A study records the number of carious lesions in a group of 8 pediatric patients: 4, 1, 0, 3, 2, 5, 1, 6. What is the median number of carious lesions for this data set?
- 2
- 3
- 2.25
- 2.5 (Correct answer)
Correct answer: 2.5
To find the median, the data must first be arranged in numerical order: 0, 1, 1, 2, 3, 4, 5, 6. Because there is an even number of data points (8), the median is the average of the two middle values (the 4th and 5th values), which are 2 and 3. The average is (2 + 3) / 2 = 2.5.
Question 3: A community dental clinic has 200 active patients. A review of their records indicates that 50 of these patients have been diagnosed with gingivitis. If a patient is selected at random, what is the probability that they have gingivitis?
- 1/5
- 1/4 (Correct answer)
- 1/3
- 1/2
Correct answer: 1/4
Probability is calculated by dividing the number of specific outcomes (patients with gingivitis) by the total number of possible outcomes (total patients). The calculation is 50 / 200, which simplifies to 1/4.
Question 4: A dental hygienist is analyzing the ages of patients who received a specific cosmetic procedure in one week. The ages recorded are: 28, 35, 26, 41, 28, 50, 28, 33. Which of the following values represents the mode of this data set?
- 28 (Correct answer)
- 33.6
- 30.5
- 24
Correct answer: 28
The mode is the value that appears most frequently in a data set. In the given list of ages (28, 35, 26, 41, 28, 50, 28, 33), the age '28' appears three times, which is more often than any other age.
Question 5: A quality control report measures the fluoride concentration (in parts per million, ppm) in five different batches of city water. The readings are: 0.7 ppm, 1.1 ppm, 0.6 ppm, 0.9 ppm, and 1.2 ppm. What is the range of these fluoride concentrations?
- 0.9 ppm
- 1.2 ppm
- 0.6 ppm (Correct answer)
- 0.5 ppm
Correct answer: 0.6 ppm
The range is the difference between the highest and lowest values in a data set. The highest value is 1.2 ppm and the lowest value is 0.6 ppm. The range is 1.2 - 0.6 = 0.6 ppm.
Question 6: A bar chart displays the results of a patient satisfaction survey for a dental practice. The percentages of 'Very Satisfied' responses for three hygienists are: Hygienist A: 85%, Hygienist B: 90%, Hygienist C: 75%. Which of the following statements accurately interprets the data?
- Hygienist C has the highest patient satisfaction.
- Hygienist A's satisfaction rating is 10 percentage points lower than Hygienist B's.
- The average satisfaction rating for the three hygienists is 85%.
- Hygienist B has the highest patient satisfaction. (Correct answer)
Correct answer: Hygienist B has the highest patient satisfaction.
By directly comparing the percentages, Hygienist B has a 90% satisfaction rating, which is higher than Hygienist A's 85% and Hygienist C's 75%. Therefore, Hygienist B has the highest patient satisfaction.
ATDH - Admission Test for Dental Hygiene Data and Probability Analysis Questions and Answers
A dental hygienist measures six periodontal pocket depths around a specific molar, recording the following values in millimeters: 3, 2, 4, 5, 3, 1.
What is the mean (average) pocket depth for this tooth?