4. in cell i4, enter a formula that uses the if function and structured references to calculate customer sales growth (as a %).
a. growth can be calculated if the value in the 2015 purchases column is greater than 0.
b. to calculate growth (as a %), divide the value in the growth ($) column by the value in the 2016 purchases column.
c. if the value in the 2015 purchases column is not greater than 0, return a value of n/a. if necessary, copy the formula you created in cell i4 to the range i5: i27.

Consider a slotted aloha system, where the time slot equals the fixed duration of each packet. assume that there are 4 stations a,b,c,d sharing the medium. (a) stations a,b,c,d receive one packet each from higher layers at times 1.3, 1.5, 2.6,5.7 respectively. show which transmissions take place when, according to the slottedaloha protocol; describe all transmissions until all four packets have been successful.when needed, each station has access to the following sequence of random number, provided by a random number generator and drawn uniformly between 0 and 1: (1) station a draws numbers: 0.31, 0.27, 0.78, 0.9, 0.9, 0.11, 0. (2) station b draws numbers: 0.45, 0.28, 0.11, 0.83, 0.37, 0.22, 0. (3)station c draws numbers: 0.1, 0.2, 0.3, 0.4, 0. (4) station d draws numbers: 0.36, 0.77, 0.9, 0.1, 0.1, 0.1, 0.1, 0. (b) in slotted aloha, a station transmits in each time slot with a given probability. what probabilities would you assign to each of the four stations so as to: (i) maximize the efficiency of the protocol? (ii) maximize fairness among the four stations? (c) will the efficiency increase or decrease if we modify slotted aloha as follows: (i) get rid of slots and allow stations to transmit immediately? (ii) implement carrier sensing? (iii) implement collision detection? (iv) implement collision avoidance?

How is the number 110 written when expanded out to place values in the base 2 (binary) number system? options: 2 x 4 + 3 x 2 + 4 x 1 1 x 2 + 1 x 2 + 0 x 2 1 x 100 + 1 x 10 + 0 x 1 1 x 4 + 1 x 2 + 0 x 1

What is the total resistance in a circuit that contains three 60 ohm resistors connected in a series? a. 20 ohms b. 120 ohms c. 60 ohms d. 180 ohms