a person

Let X1, X2, ..., Xn be independent normal random variables such that X_i has a normal distribution with mean mu_i and variance sigma_i squared.

a.) Find the distribution of

Y = (sum from i=1 to n) a_i X_i where a1, a2, ..., a_n are fixed constants.

b.) If X1, X2, ..., Xn are independent normal r.v.'s with the same mean mu and variance sigma squared, find the distribution of

X bar = [((sum from i=1 to n) X_i) / (n)]

Sorry about the ugly formatting here, but could someone point me in the right direction here? I think the solution might involve moment-generating functions? The question doesn't really seem too difficult and I can more or less understand what it's asking conceptually, I'm just not sure how to go about solving it.

Assume that a hard disk has the following characteristics:

Rotation speed = 7,200 rev/min

Arm movement time = 0.5 msec fixed startup time + 0.05 msec for each track crossed. (The startup time is a constant no matter how far the arm moves.)

Number of surfaces = 2 (This is a double-sided disk. A single read/write arm holds both read/write heads.)

Number of tracks per surface = 500

Number of sectors per track = 20

Number of characters per sector = 1024

What is the worst-case time required to read the entire contents of the disk; that is, to read every single sector on the disk? Assume the read arm is initially positioned at the beginning of the first sector of the first track, and that every track must be read from the very beginning, that is, from the very first sector on that track.

I would like to know what people think of the song "Forgive You" by the band Vedera. So, please listen to the song if you don't already know it (it should be easy to find on YouTube) and provide your reaction.

How can you determine the concentration of CO2 in a soda can using just a balance and a graduated cylinder (and a calculator)?

A hint given is that soda cans are over-pressurized with CO2 and not filled all the way to the top.

Which of the following pairs of substances are miscible?

~Water and alcohol (isopropanol)

~Water and food coloring

~Alcohol and food coloring

~Water and salt

~Alcohol and salt

Which of the following conduct current?

~Water

~Alcohol

~Food coloring

~Salt and water mixture

~Salt

Which of the following substances are flammable?

~Water

~Alcohol

~Food coloring

~Salt and water mixture

~Salt

Could someone please tell me what "a la milanesa" means in English?

No necesita ser tomado literalmente..... Can tomar be used in this way?

I know there is a Spanish word "lector," which means "reader." I'm just not positive what kind of reader it means. Basically, what I want to be sure of is: Can it be used to mean reader as in, someone who reads a book -- Like, in this sentence: "The author leaves the ending up to the reader's imagination" ?

Just want to be sure =)

Can someone show me how to solve this problem please?

Can someone explain the answer to this question please?

Could someone help me with this question please?

Can someone explain how to solve this problem please?

Can someone explain how to solve this problem please?