Statistics and Probability Answers

The mean age of a group of persons is 40 , another group has mean age 48, if the ratio of number of persons in two groups is 5:3, find the mean age of all the persons in two groups?

The mean age of a group of persons is 40 , another group has mean age 48, if the ratio of number of persons in two groups is 5:3, find the mean age of all the persons in two groups

A problem in mathematics is given to three students A, B and C whose chances of solving it are 1/3, 1/4 and 1/5 respectively. find the probability that the problem will be solved

Find the probability of obtaining 6 or more hads when an ordinary coin is tossed 10 times. Calculate also the approximate probability of obtaining more than 90 heads when the coin is tossed 100 times.

Q. less the variability exist, the more an average is representative of a set of data. What's the meaning of statement? elaborate with example.

A spinner is divided into 8 equal sections what is probability of spinning 1 or any odd number??

A draw is going to be played in 14 people. Selectors would select 6 people. Then what is the winning percentage of individual person ?

Assume I have box of 200 matching black socks but 10 of those socks have a hole.
If I randomly select 3 socks from the box what are the odds that all 3 socks will have a hole.

Calculate mean and standard deviation for the following two series:
a. Series A: 48,50,50,52,52
b. Series B: 40,70,50,60,30

Hello
I have 2 questionnaires, one from managers of a company & the other from personnel. the first measures managers commitment & the second measures the personnel satisfaction. i want to correlate & regression between two questionnaire. but the number of two population is not equal. if i could? and how?
thanks