1. ## Hypothesis Testing

Hi I have this question.

If $26$ of $200$ tyres of $brand A$ failed to last $20,000$ miles, while the corresponding gures for $200$ tires of $Brands B$, $C$, and $D$ were $23$, $15$ and $32$, test the null hypothesis that there is no di erence in the quality of the four kinds of tyres.
Use $\alpha = 0.05$.

Thank-you so much!

2. Originally Posted by lpd
Hi I have this question.

If $26$ of $200$ tyres of $brand A$ failed to last $20,000$ miles, while the corresponding gures for $200$ tires of $Brands B$, $C$, and $D$ were $23$, $15$ and $32$, test the null hypothesis that there is no dierence in the quality of the four kinds of tyres.
Use $\alpha = 0.05$.

Thank-you so much!
What have you done? What specific difficulties do you have with this question?

The null hypothesis is that there is no difference.

CB

3. What kind of test should I use for this particular distribution?

4. Originally Posted by lpd
What kind of test should I use for this particular distribution?
The number of failure in 200 trials with a given probability p has a binomial distribution B(200,p), which you can probably approximate in this case by a normal. You now need to find an interval such that the probability of none of four observations from this distribution are out side is 5%.

CB