Twenty different statistics students are randomly selected. for each of them, their body temperature (degrees°c) is measured and their head circumference (cm) is measured. if it is found that r=0, does that indicate that there is no association between these twovariables?
choose the correct answer below.
a. yes, because if r =0, the variables are completely unrelated.
b. no, because while there is no linear correlation, there may be a relationship that is not linear.
c. no, because if r=0,the variables are in a perfect linear relationship.
d. no, because r does not measure the strength of the relationship, only its direction.

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