Which of the following relations is a function?
{ (1, 2), (1, 3), (1, 4), (1, 5) }
{ (1, 3), (2, 3), (4, 3), (9, 3) }
{ (5, 4), (-6, 5), (4, 5), (4, 0) }
{ (6, -1), (1, 4), (2, 3), (6, 1) }

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec