A retail shop manager analyzed the relationship between sales and the method of payments. Based on his analysis, he has produced the following joint probability table, as shown below: Size of purchase Method of payment Cash Credit card Debit Card Under $20 0.09 0.03 0.04 $20 -$100 0.05 0.21 0.18 Over $100 0.03 0.23 0.14 a. What proportion of purchases were paid by debit card? (2 marks) b. What proportion of purchases were paid by cash? (2 marks) c. Determine the proportion of purchases made by credit card or by debit card? (2 marks) d. Are the events “payment by cash” and “purchase of under $20” mutually exclusive? Explain your answer.

Acable company wants to provide cell phone service for residents on an island. the function for the cost of laying the cable from the island to the mainland is c(x)= 6.500 square root x2+4, where x represents the length of the cable in feet. what are the domain and range of the function? a) domain: all real numbers range: all real numbers greater than or equal to 17,000 b) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 17,000 c) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 13,000 d) domain: all real numbers greater than or equal to 13,000 range: all real numbers greater than or equal to 0

Evaluate the expression for the given value of the variable. | ? 4 b ? 8 | + ? ? ? 1 ? b 2 ? ? + 2 b 3 -4b-8+-1-b2+2b3 ; b = ? 2 b=-2

3.4a=57.8 what is the the value of a