7. You are observing a radar signal sequence
where θ is an unknown constant and is N(0,1) and independent and identical over time index k. Given m observations of , i.e., given {Y1, Y2,..., },
(b) Is your estimate unbiased, i.e., does the mean of your estimate equal θ? Why? (4%)
(a) How do you estimate the value of θ? (5%)
6. X and Y are two random variables with a joint probability density function as
(c) Is the correlation coefficient ρXY = 0? Explain why. (5%)
50. How many of the following statements are false? I: the Group 3A elements are all metals, II: alkaline earth metals react less vigorously with water than do alkali metals, III: salts can consist of hydrogen, IV: because Li is the strongest reducing agent among the alkali metals, it reacts most quickly with water of the alkali metals (A) 0 (B) 1 (C) 2 (D) 3 (E) 4
49. Choose the metal that reacts least vigorously with water. (A) Mg (B) Ca (C) Sr (D) Ba (E) all of these react equally vigorously with water
48. Which of the following elements exhibit(s) the oxidation states +1 and +3? (A) B (B) Al (C) Ga (D) T1 (E) none of these
This is a large modal.