probability

why does the worked solution for this question use P(Z > -1.64485) instead of P(Z > 1.64485)? I don't understand why they made this negative.

Can someone please explain how the worked solution got (7/8)^n-1 for part (ii)? If we are finding the geometric sum, wouldn't r = 7/8?

this question is part of a 'using counting in probability' part of my textbook and i'm stuck on part (d). i tried working it out, but my answers are different from the textbook's (which is 1/425). any help would be appreciated <3

I just started learning this topic so please don't laugh at me if you find this question easy but I can't do any of these ..... Can you guys please help me out with this entire question??

I stumbled upon this question from the MANSW textbook. It is part g) and h) that are troubling me What does three of a kind mean? And how do I do those parts?

I have been having trouble with understanding what PDF and CDF probability topics are. Can someone please give a summary with things that are unique to these functions? Such as any identities, rules, etc. Thank you.

Hi all, Can someone help spot my error? Answer is n=17 apparently. Q: A card is selected from a pack, its suit is noted, and it is returned. How many times must this be done so that the probability of at least one heart is more than 99%? P(X>=1) = 1-P(X=0) > 0.99 P(X=0) < 0.01 solve for n...

Hi Mathematicians, I need help on question D, i think it's impossible to solve. Question asks: a 5 digit number is chosen at random. Find the probability: d) that the digits are distinct and in increasing order. Good luck!

I was wondering if someone could help me with this question? this one has really confused me, and unfortunately is worth 14 marks. Q: Wildlife biologists inspect 157 deer taken by hunters and find 33 of them carrying ticks that test positive for lyme disease. Previous data indicates that the...

Hi, I would appreciate if someone could help me with a question that I need the answer to before Sunday (10th may?) I have tried for so long to answer this questions but I truly do not know how. I don’t even know/understand what parts to calculate and how to do it. I’m really struggling here...