0:00
All right.
00:02
So we have a manufacturer of a truck tire.
00:07
They claim the mean mileage, the tire can be driven before the tread wears out is 60 ,000 miles.
00:14
And assuming this is a normally distributed mean, but the mileage wear follows the normal distribution.
00:23
And given the standard deviation, a certain company bought 48 tires and found the mean for mileage for the trucks.
00:35
Was 59 ,500 miles before they needed to change the tires.
00:42
And is this company's experience different from that claimed by the manufacturer at the 0 .05 significance level? so we wanna know, is it different? so we're just basically looking at is the mean, so mu, you, let's say you, is it, we're gonna say that is equal to 60 ,000.
01:04
And so then the alternative hypothesis be that is no it is not equal to 60 ,000.
01:12
That's all it's looking for.
01:15
Is it different? is it greater than or less than just different? not the 60 ,000 miles.
01:22
So those are our hypotheses.
01:24
And the decision rule at the 0 .05 level of significance.
01:29
So it's a two -tail test...