The mean of 5 different numbers is 6 and the mean of 4 different numbers is 15. Find the mean of 9 numbers.​

Write two point-slope equations for the line passing through the points (6, 5) and (3, 1)

Ahyperbola centered at the origin has a vertex at (-6,0) and a focus at (10,0)

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