A particular brand of tires claims that its deluxe tire averages at least 50,000 miles before it needs to be replaced. A survey of owners of that tire design is conducted. From the 28 tires surveyed, the average lifespan was 46,500 miles with a standard deviation of 9800 miles. Do the data support the claim at the 5% level?
My null hypothesis:μ greater than/equal to 50,000
Alternative hypothesis:μ is less than 50,000
Test statistic: 25.1
P-value: 1

Is everything right so far? Also how do I know when to reject or fail to reject?

Question

A particular brand of tires claims that its deluxe tire averages at least 50,000 miles before it needs to be replaced. A survey of owners of that tire design is conducted. From the 28 tires surveyed, the average lifespan was 46,500 miles with a standard deviation of 9800 miles. Do the data support the claim at the 5% level?
My null hypothesis:μ greater than/equal to 50,000
Alternative hypothesis:μ is less than 50,000
Test statistic: 25.1
P-value: 1

Is everything right so far? Also how do I know when to reject or fail to reject?