b) The probability that the sample mean is between $3.78 and $3.86 P(3.78

b) The probability that the sample mean is between $3.78 and $3.86 P(3.78 < X < 3.86) = P(3.78 < Z < 3.86) P(3.78 - 3.82 < z < 3.86 - 3.82) < 0.7666) - < -0.7666) 0.33/v140 0.33/440 P (-0.04 < z < 0.04) 0.052177 0.052177 P (-0.7666 < z < 0.7666 0.77834 0.5567 0.22166