Confidence Intervals for Means

We are 95% confident that the true mean caloric content can be found with a sample of 150 to 350 cupcakes.

We are 95% confident that the interval (150, 350) captures the true average caloric content.

We are 95% confident that a sample of 20 cupcakes will find 250 calories per cupcake.

None of these are correct.

89.08 < μ < 94.92

87.27 < μ < 96.73

87.29 < μ < 96.71

87.77 < μ < 96.23

(1070, 2530)

(1273, 2326)

(1799, 1801)

(1776, 1823)

7.70 < μ < 12.42

n

n+1

1-n

n-1

90% of the sampled CEOs have salaries that fell in the interval $139,048 to $154,144

We are 90% confident that the mean salary of all CEOs in the electronics industry falls in the interval $139,048 to $154,144.

There is a 90% chance that CEOs in the electronics industry have salaries that fall between $139,048 to $154,144

We are 90% confident that the mean salary of the sampled CEOs falls in the interval $139,048 to $154,144.

25

50

600

2.064

12

2.201

2.40

0.2

95% confident the sample mean is between 580.4 and 619.6

95% confident the population mean is between 583.55 and 616.45

95% confident the population mean is between 579.36 and 620.64

95% confident the population mean is between 574.2 and 625.8