probabbility

5 Fit the curve y = ax to the following data by least square method. X 2 3 4 5 6 y 2.98 4.26 5.21 6.1 6.8 7.5 6 Find the coefficient of correlation and regression lines to the following data X 5 7 8 10 11 13 16 V 33 30 28 20 18 16 9 7 A man returns home at night during a blackout (without a flash light) with a bunch of n keys, one of which will unlock his front door. He tries to unlock the door with one key after the other, each chosen at random from the bunch at hand independently of previous choices. Find the expected number of trials until the door is unlocked for the following two different cases: a. If he removes from the bunch key that is tried and found unsuitable. b. If keys that are found unsuitable are not removed from the bunch and can be chosen and tried again