Option D is the correct answer because it involves randomly selecting a sample of light bulbs from different classrooms. By choosing 10 classrooms on each floor randomly, the maintenance worker can ensure a representative sample of the entire population of light bulbs in the school. This method helps to reduce bias and provides a more accurate estimate of the overall condition of the light bulbs in the school.
Options A, B, and C do not involve random selection and may introduce bias into the estimation process. For example, only inspecting all the light bulbs in the sixth grade classrooms may not provide a full picture of the condition of light bulbs in other classrooms. Similarly, only inspecting light bulbs from rooms on the second floor or in classrooms not currently being used may not be representative of the entire population of light bulbs in the school.
A school maintenance worker wants to estimate how many of the 1,000 light bulbs in their 55 classrooms need a new light bulb. Which of the following is a random sample of light bulbs to be inspected.
A. All the light bulbs in the sixth grade classrooms.
B. All the light bulbs from rooms on the second floor of the school.
C. All of the light bulbs in the classrooms not currently being used.
D. 10 classrooms on each floor chosen randomly.
The correct answer is D. Please show why that answer is correct. Thank you very much.
1 answer