Acollege statistics professor has office hours from 9am to 10: 30am daily. a sample of waiting time to see the professor(in minutes) is 10,12 20, 15, 17, 10, 30, 28,35, 28, 19, 27, 25, 22, 33, 37, 14, 21, 20, 23. assuming standard deviation is 7.84, find the 95.44% confidence interval for the population mean.
a) -7.7 to 7.8 minutes
b) 19.5 to 35.1 minutes
c) -3.5 to 3.5 minutes
d) 18.8 to 25.8 minutes

Option D) 18.8 to 25.8 minutes

Step-by-step explanation:

We are given the following data set:

10,12,20, 15, 17, 10, 30, 28,35, 28, 19, 27, 25, 22, 33, 37, 14, 21, 20, 23

Standard deviation = 7.84

Confidence level = 1 - Significance Level = 1 - 95.44% = 4.56% = 0.0456

Formula:

Confidence interval:

Putting the values, we get,

The confidence interval is (18.8,25.8).

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form

stop cheating

step-by-step explanation: