Math Answers

A medical centre reports that the average cost of rehabilitation for stroke victims is 24672 BD. To see if the average cost of rehabilitation is different at a particular hospital, a researcher selects 35 victims at random and find the average cost is 26343 BD. Standard deviation is 3251 BD. At α=0.01, can it be concluded that the average cost of rehabilitation at a particular hospital is different form 24672 BD

4. Number of calls coming to customer care of mobile company per minute is a poisson random variable with mean 5. Find the probability that no calls are in certain minute.

A nutritionist wants to know the populatiin proportion of grade 11 students who eat vegetables. Pegged at a confidence of 95% survey among 1200 respondents was conducted and 200 said that they eat vegetables.

a.What is the margin of error?

b.Construct the confidence interval

c.Find the length of the confidence interval

A nutritionist wants to know the population proportion of grade 11 students who eat vegetables . Pegged at a confidence of 95% survey among 1200 respondents was conducted and 200 said that they eat vegetables. What is the margin of error???

45* . Prove that if a, b, c are three different integers, then there exist in-

finitely many positive integers n such that a+n, b+n, c+n are pairwise rel-

atively prime. 

44. Prove that if a and b are different integers, then there exist infinitely 

many positive integers n such that a+n and b+n are relatively prime. 

43. Prove that there exists an increasing infinite sequence of tetrahedral 

numbers (i.e. numbers of the form T_n = 1/6 n(n+ 1)(n+2), n = 1,2, ... ), such 

that every two of them are relatively prime. 

42. Prove that there exists an increasing infinite sequence of triangular 

numbers (i.e. numbers of the form t_n = -1/2 n(n+ 1), n = 1, 2, ... ) such that 

every two of them are relatively prime. 

41. Prove that for every integer k the numbers 2k+1 and 9k+4 are rel-

atively prime, and for numbers 2k-1 and 9k+4 find their greatest common 

divisor as a function of k.