Suppose that the iqs of university​ a's students can be described by a normal model with mean 140 and standard deviation 8 points. also suppose that iqs of students from university b can be described by a normal model with mean 120 and standard deviation 11.a) slect a student at random from university a. find the probability that the student's iq is at least 135 points. b) select a student at random from each school. find the probability that the university a students iq is at least 5 points highter than the university b students' iq. c) select 3 university b students at random. find the probability that this group's average iq is at least 115 points.

0.0266, 0.9997,0.7856

Step-by-step explanation:

Given that the IQs of university​ A's students can be described by a normal model with mean 140 and standard deviation 8 points. Also suppose that IQs of students from university B can be described by a normal model with mean 120 and standard deviation 11. Let x be the score by A students and Y the score of B.

A)

B) Since X and Y are independent we have

X-Y is Normal with mean = 140-120 =20 and

C) For a group of 3, average has std deviation =

the ratio of white tiles to blue tiles is 48: 16. the ratio in it's simplest form is 3: 1.

step-by-step explanation:

ratio: take the first number and add a colon next to it, then add the second number after that. make sure the ratio order matches up with the written problem!

simplest form: we can simplify the ratio 48 : 16 by dividing both terms by the greatest common factor (gcf).

the gcf of 48 and 16 is 16.

divide both terms by 16:

48 ÷ 16 = 3

16 ÷ 16 = 1

reducing to simplest form:

48 : 16 = 3 : 1

x is greater than 5

step-by-step explanation:

2x+7 is greater than 17

    -7                           -7

2x is greater than 10

divide by 2 each side

x is greater than 5