# Thread: Need help with stats (4)!

1. ## Need help with stats (4)!

Hi everybody,

i would first like to apologise, in case i am posting this under the wrong section, as i am a new member. I am in need of help of some stats questions, please help me by providing answers and if possible, some explanation to it.

Thank you all!

10. (a) “If you know that the probability that a normal variable exceeds a certain number
Q, is 0.10, you can be sure that this variable is less than –Q is also 0.10.”Do you
agree? Why or why not?
(b) It was reported that the average annual amount American households spend for
daily transportation is $6312. Assume that the amount spent is normally distributed. i). Suppose you learn that 5% of American households spend less than$1000 for daily transportation. What is the standard deviation of the amount spent? Using this fact answer:
ii) What is the probability that a household spends between $4000 and$8000?
iii) What is the range of spending for the 3% of households with the highest daily transportation cost?

i have tried to attempt these questions and have answers for some of them, but i am not sure if i am correct. please help me!

thank you so much in advance

2. Originally Posted by xsyenex
Hi everybody,

i would first like to apologise, in case i am posting this under the wrong section, as i am a new member. I am in need of help of some stats questions, please help me by providing answers and if possible, some explanation to it.

Thank you all!

10. (a) “If you know that the probability that a normal variable exceeds a certain number
Q, is 0.10, you can be sure that this variable is less than –Q is also 0.10.”Do you
agree? Why or why not?
(b) It was reported that the average annual amount American households spend for
daily transportation is $6312. Assume that the amount spent is normally distributed. i). Suppose you learn that 5% of American households spend less than$1000 for daily transportation. What is the standard deviation of the amount spent? Using this fact answer:
ii) What is the probability that a household spends between $4000 and$8000?
iii) What is the range of spending for the 3% of households with the highest daily transportation cost?

i have tried to attempt these questions and have answers for some of them, but i am not sure if i am correct. please help me!

thank you so much in advance
These begin to look like a pre course test, you should be doing these on your own so that the lecturer can determin what you do and do not know.

CB

3. hi captainblack,

these questions are part of my homework assignment...

4. Originally Posted by xsyenex
hi captainblack,

these questions are part of my homework assignment...
Which counts towards your final grade ....? Please read the appropriate forum rule (forum rules are stuck at the top of every subforum).