Question

ch 8 a group of veterinarians at a major veterinary hospital was interested in investigating a possible link between enteroliths, stones that form in the colon of horses, and diet. they decided to conduct a survey of feeding practices of horses admitted to the veterinary hospital. to obtain a simple random sample they used a computer to generate 4-digit id numbers for all horses. they used random digit tables to select the horses. which of the following are steps in selecting a random sample by this procedure?
discard any sequence that does not correspond to a horse id and move to the next 4 digits.
pick a random starting point in the table and read 4 digits.
read 4 digits across a line and if the 4 digits correspond to a horse id, select the animal.

Explanation:

To select a simple random sample using random digit tables for horse IDs (4 - digit):

1. First, we need a random starting point in the table to begin reading digits. So "Pick a random starting point in the table and read 4 digits" is a valid step.
2. When reading the 4 - digit sequences, if a sequence does not match any horse ID, we discard it and move to the next 4 - digit sequence. So "Discard any sequence that does not correspond to a horse ID and move to the next 4 digits" is a valid step.
3. When we read 4 digits, if they correspond to a horse ID, we select that horse. So "Read 4 digits across a line and if the 4 digits correspond to a horse ID, select the animal" is a valid step. All three listed steps are part of the procedure for selecting a simple random sample using random digit tables for this scenario.

Answer:

• Discard any sequence that does not correspond to a horse ID and move to the next 4 digits.
• Pick a random starting point in the table and read 4 digits.
• Read 4 digits across a line and if the 4 digits correspond to a horse ID, select the animal.