1. A manufacturer of sprinkler systems designed for fire protection claims that the average activating temperature is at least 135F. To test this claim, you randomly select a sample of 32 systems and find the mean activation temperature to be 133F. Assume the population standard deviation is 3.3F. At=0.10, do you have enough evidence to reject the manufacturer's claim?
2. Claim:=40;=0.05;=1.97. Sample statistics:x=39.2,n=25. Assume the population is normally distributed.
3. A company claims that the mean battery life of their MP3 player is at least 30 hours. You suspect this claim is incorrect and find that a random sample of 18 MP3 players has a mean battery life of 28.5 hours and a standard deviation of 1.7 hours. Is there enough evidence to reject the claim at=0.01?
4. Claim: >25;=0.05. Sample statistics:x=26.2,s=2.32,n=17. Assume the population is normally distributed.
5. A research center claims that at most 18% of U.S. adults' online food purchases are for snacks. In a random sample of 1995 U.S. adults, 20% say their online food purchases are for snacks. At=0.10, is there enough evidence to support the center's claim?