Answer:
350 lightbulbs
Step-by-step explanation:
First, we need to find the rate of lightbulbs that are inspected. This can be calculated as the division between the number of lightbulbs selected for inspection and the number of light bulbs produced. This is:
Rate = 7/400 =0.0175
That means that for every lightbulb produced, 0.0175 are inspected. Then if the factory produces 20000 light bulbs, the number of light bulbs inspected is:
20000*0.0175 = 350 lightbulbs
