orange and lemon multiple choice q

[asapwhat]

Can someone throw me their solution to the orange and lemon mcq, for some reason I couldn't reach any of the given options.

[shortgame11]

think there wasnt an answer lol

[Matteus]

Got 3root17 for the standard deviation??

[dave101]

Legitimately think I failed. Gussed about half of questions on multi choice, blanked out on so many questions. Rip me

[BNard]

All this time I thought variance for combination of variables was a squared var(x) + bsquared var(y) but it wasn't an answer for mc:(

[chiiia]

I got A (SD=3root29), only way it turned out as an answer.

Found sample SD of both oranges and lemons then squared it to get variance. Found 9*Var(oranges)+4*Var(lemons), then square rooted it.

[Callum@1373]

A for me, you got to the answer by not squaring the coefficient of the variance since it was repeat selection

[BNard]

Temporarily using this as the exam discussion thread -

How did everyone go about finding the obtuse angle between the he paths of the vectors?
I had no idea, did some weird trig and got 90.4

[angrypotato1]

A for me, you got to the answer by not squaring the coefficient of the variance since it was repeat selection

Yep can confirm

Temporarily using this as the exam discussion thread -

How did everyone go about finding the obtuse angle between the he paths of the vectors?
I had no idea, did some weird trig and got 90.4

I got the gradients of the lines, then the tangent of each. Make a triangle, subtract from 180 to find the missing angle. Ended up with about 103?

[Eefy]

Temporarily using this as the exam discussion thread -

How did everyone go about finding the obtuse angle between the he paths of the vectors?
I had no idea, did some weird trig and got 90.4

I found the velocity vector of both ships and dot product. Ended up with around 97 degrees?

[tomp14]

I turned it into a triangle, found two angles and subtracted both from 180 to get around 97 degrees.