To determine the proportion of bulb life that is greater than or equal to 900 hours using a histogram, we need to follow a series of steps to calculate the proportion. Unfortunately, since no histogram data is provided in the question, I will outline the process you would take if you had the histogram data.
1. Interpret the histogram: First, look at the histogram to understand how the data is distributed. The histogram should show you the frequency of bulb life in different intervals.
2. Identify intervals greater than or equal to 900 hours: Find the histogram bar(s) that represent the bulb life greater than or equal to 900 hours. The bars will correspond to specific intervals (e.g., 900-999 hours, 1000-1099 hours, etc.).
3. Calculate frequency for each interval: For the intervals you identified in step 2, determine the frequency (how many bulbs) of each of those intervals. This should be either directly readable from the histogram or provided in a frequency distribution table that accompanies the histogram.
4. Sum the frequencies from step 3: Add together the frequencies of all intervals that are greater than or equal to 900 hours to get the total number of bulbs that have a life of at least 900 hours.
5. Find the total number of bulbs: Determine the total number of bulbs in the sample by adding up the frequencies for all intervals in the histogram.
6. Divide to get the proportion: Divide the sum of frequencies for intervals greater than or equal to 900 hours (from step 4) by the total number of bulbs (from step 5). This will give you the proportion of bulbs that have a life of at least 900 hours.
7. Convert to a decimal: Ensure that your final answer is in decimal form. Do not round your answer if the instruction specifies to provide the exact value.
Since no specific numbers are given, we can't perform these calculations, but here's an example of how the calculation might work with hypothetical data:
- Suppose the histogram shows that there are 20 bulbs with a life between 900-999 hours, 15 bulbs with a life between 1000-1099 hours, and so on.
- Let's also say the total number of bulbs is 100.
- If only the intervals from 900 hours and above are of interest, and let's say that sums up to 50 bulbs in total in those intervals.
- The proportion would then be 50 bulbs / 100 bulbs total = 0.5.
The actual numbers will vary depending on the specific histogram data, and to provide the exact proportion, you will need to follow the process outlined above with the actual numbers from your histogram.