Science & Mathematics - 1 November 2006

Can anyone help? Please show working. Thank you!

1.Let X be a random variable with a normal distribution with mean 4 and standard deviation 2 and let Z be a random variable with the standard normal distribution.
a) Find Pr(X>4)

2006-11-01 17:58:05 · 2 answers · asked by Anonymous in Mathematics

2006-11-01 17:55:58 · 5 answers · asked by jose 4 in Geography

I'm confused as how to apply log laws when it comes to solving problems such as this. Where would everything be appropriate.
Step by step help would be greatly appreciated. It would help to answer other answers aswell.

Bacteria is growing according to formula M=M(subscript o)x10^np, where M is the number present after p weeks.
-State M(subscript 0) if the number is initially 400
-Find n if the number present is doubled after 3 weeks.
-Find how long it takes to the nearest day, to triple the original number.

2006-11-01 17:48:29 · 3 answers · asked by o_fungus.amongus_o 1 in Mathematics

2006-11-01 17:46:29 · 5 answers · asked by Mileesh M 1 in Geography

My English Lit. teacher (who's also head of the dept.) told me that he heard about a year ago that scientists had found that the development of stalagmites and stalactites was influenced by sounds in the cavern, that the developing layers were soft enough to be compressed by sound waves, and that this meant that they might potentially record sound - in theory allowing us to hear ancient conversations.

If this is true, it's some of the most exciting news I've ever heard. However, I can't find any references to this idea. Has anyone else heard of this and can provide me with references?

2006-11-01 17:42:15 · 7 answers · asked by ? 1 in Earth Sciences & Geology

2006-11-01 17:40:14 · 17 answers · asked by Anonymous in Medicine

I've gone blank! Can someone please shown me how to differentiate this question? Please show working

V= (1/3) pi r^2 h

2006-11-01 17:38:15 · 3 answers · asked by Anonymous in Mathematics

of the distance. If a substance requires 3 seconds to diffuse 10 mm, how long will it take to diffuse 20 mm? Please, explain your answer.

2006-11-01 17:37:00 · 1 answers · asked by curious 2 in Biology

A porcupine bit me what should I do?
I went out to get some wood for the fire and a porcupine bit me right above the wrist. Are they venomous? Should I go to the hospital? I don't feel good

2006-11-01 17:35:48 · 14 answers · asked by Anonymous in Zoology

the question: In the xy-plane, line j passes through the origin & is perpendicular to the line 4x + y = k, where K is a constant. If the two lines intersect at the point (v,v+1), what is the value of v?

2006-11-01 17:35:42 · 5 answers · asked by vnnd 1 in Mathematics

2006-11-01 17:35:35 · 3 answers · asked by Gaby 1 in Medicine

when you are makeing a shadow on the wall and you move your hand how long dose it take for your shadow to catch up to were your hand stop? it is not at the same time nor is it as far behind of your hand but it is close, right? i think the answer is darkness has the same speed as light does, but what about a shadow's reaction time? what is it?

2006-11-01 17:35:30 · 6 answers · asked by jesse g 1 in Physics

The points (0,4), (0,0), (6,0) are on a circle in the X-Y plane. What is the radius of the circle?

2006-11-01 17:29:06 · 4 answers · asked by Jackie...boy 1 in Mathematics

How does say the Hubble telescope aim itself?

Every action creates an opposite reaction blah blah. I would think that simply using an internal motor to swivel the camera would be fruitless.

I cannot imagine that thing having sufficient rocket propellant for it to operate for years between services.

2006-11-01 17:28:21 · 4 answers · asked by managuense 1 in Astronomy & Space

like plasma membrane, mitochondria is said a living organelle while cell wall is a non living one
also why do we say blood platelets are non living

2006-11-01 17:28:03 · 2 answers · asked by muchacho_fresco 2 in Biology

2006-11-01 17:27:26 · 3 answers · asked by Anonymous in Zoology

2006-11-01 17:25:44 · 4 answers · asked by soccerman2431 1 in Mathematics

2006-11-01 17:24:41 · 7 answers · asked by LP 1 in Chemistry

2006-11-01 17:23:56 · 4 answers · asked by Timothy W 1 in Engineering

In a math club of sixty members, each member either owns a computer or a chess set or both. One-half of those who own a computer also own a chess set. One third of those who own a chess set also own a computer. How many members own both?

2006-11-01 17:23:17 · 1 answers · asked by Jackie...boy 1 in Mathematics

2006-11-01 17:21:57 · 15 answers · asked by pradosh Kumar.c.v c 1 in Biology

in my personal opinion, the human brian is one of the most wonderful machines that has ever been created, actually i think is the most wonderful one, because from where came the idea of all the computers, machines, factories, cars, etc.?? esactly from the human brain. The brian is the one that makes us feel, love, think etc and enjoy life. And it also performs actions that are needed to survive like breathing, heart bumping, body temperature, and it also makes function to make our live better, like taste, sight etc. The brain and its two hempispheres, their lobes, and their functions are needed for our lives to be completley wonderful.

2006-11-01 17:21:40 · 6 answers · asked by glenda trevino 1 in Medicine

check the picture link below

http://www.freewebs.com/exlfsp/madtri.bmp

You will see that the pieces are the same in both triangles. Why is there an empty space?

2006-11-01 17:20:21 · 3 answers · asked by brian f 1 in Mathematics

Just curious.

2006-11-01 17:18:16 · 7 answers · asked by irf d 2 in Geography

If 5x^2+5x+xy=2 and y(2)= –14 , find y'(2) by implicit differentiation and please show the steps. thanks!

2006-11-01 17:17:23 · 3 answers · asked by tashita 2 in Mathematics

can anyone tell me detailed about microbiology couse?people said that it is a dangerous course cuz all the virusses,microorganisms involved.is there any possibility that we ll get infected when doing research or experiements?and how s the qualifications to be taken account into to get the course?

2006-11-01 17:16:36 · 3 answers · asked by Anonymous in Biology

2006-11-01 17:15:19 · 9 answers · asked by pradosh Kumar.c.v c 1 in Biology

i have a project and it's graphing an x and y coordinate using microsoft excel, can you help me and provide the steps on how to graph it?

2006-11-01 17:14:29 · 4 answers · asked by babe 1 in Mathematics

2006-11-01 17:13:42 · 7 answers · asked by soccerman2431 1 in Mathematics

in the defenition, it says that hazel eyes are between brown and blue....
so why r my hazel eyes brown and greenish?

2006-11-01 17:13:17 · 2 answers · asked by Anonymous in Biology