The prices in dollars for a graphing calculator are shown below for 8 online vendors. Estimate the population standard deviation in price with 90% confidence.
148 133 136 152 140 143 129 139
A) 5.4 < symbol < 13.7
B) 6.4 < symbol < 12.3
C) 7.1 < symbol < 10.3
D) 7.3 < symbol < 7.9