In cell f2, enter a formula using countifs to count the number of rows where values in the range named cost have a value less than 500 and cells in the range named category have the value computer expense.

1. technician a says horsepower information can be used by consumers to compare the power of different automobile engines. technician b says that manufacturers will often list the horsepower output of their engines in the online service information. who is right?

Light travels at a speed of 186,000 miles a second. the distance light travels in a year is 5,865,690,000,000 miles/year 5,865,695,000,000 miles/year 58,656,950,000,000 miles/year 6,789,000,0000 miles/year

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?