Horn lengths of Texas longhorn cattle are normally distributed. The mean horn spread is 60 inches with a standard deviation of 4.5 inches,
Calculate the range of horn lengths for the middle 68%.] of Texas longhorn cattle.
a. 60 in. - 54.5 in.
b. 55.5 in. - 64.5 in.
c. 51 in. - 60 in.
d. 51 in. - 69 in.
The middle 68% of a normally distributed population falls within one standard deviation of the mean on either side.
Therefore, to calculate the range of horn lengths for the middle 68%, we need to subtract and add one standard deviation from the mean:
Lower bound: 60 in - 4.5 in = 55.5 in
Upper bound: 60 in + 4.5 in = 64.5 in
So the answer is b. 55.5 in - 64.5 in.