(a+1)+(b-2)i=6+7i Solve for a and b

Need asap. solve for the following inequality

Abby is collecting rainfall data. she finds that one value of the data set is a high-value outlier. which statement must be true? abby will use a different formula for calculating the standard deviation. the outlier will increase the standard deviation of the data set. the spread of the graph of the data will not change. abby will not use the mean when calculating the standard deviation.

Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.