A simple random sample of size n=40 is drawn from a population. The sample mean is found to be x=121.2 and the sample standard deviation is found to be s=12.2. Construct a 99% confidence interval for the population mean. The lower bound is nothing . (Round to two decimal places as needed.)

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116

answer: c

(2, -4)

goes 7 to the

(9, 4)

easy