Hey folks I've got a Q about what I should make my null hypothesis...

The actual question i'm fine with and know what the outcome shows but I dont know if I have the null hypothesis right. (i.e. should it be the other way round?)

So Q is...

For the sample in data set 1 use the sign test to test whether the median transit time differs from 3.50 seconds.

Data set 10 is...

Appearance transit times (seconds) of a bloodmarker for 11 patients with significantly occluded right coronary arteries.

1.80 | 3.30 | 5.65 | 2.25 | 2.50 | 3.50 | 2.75 | 3.25 | 3.10 | 2.70 | 3.00

The median transit time ($\displaystyle M_0$) was originally thought to be 3.50 seconds.

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My null hypothesis was,

$\displaystyle H_0 : M = M_0$, where $\displaystyle M$ denotes the actual median

And my answer came out to be, using a two tailed binomial test, that there was evidence at the 2.5% level to suggest median was not 3.5 and so we reject the null hypothesis.

Is this the right way to construct a null hyp? Or should it be $\displaystyle H_0 : M \neq M_0$?