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Sampling Distribution of Sample Proportion
8. Sampling Distributions & Confidence Intervals: Proportion / Sampling Distribution of Sample Proportion / Problem 4
Problem 4

A company produces a new type of LED bulb and claims that 80%80\% of the bulbs last more than 10,00010,000 hours. To verify the claim, a random sample of 120120 bulbs is tested. The quality assurance team decides that if fewer than 9090 bulbs pass the test, they will reject the company’s claim. What is the probability that the claim will be rejected, assuming the company's claim is true?