Question

1) You measure 33 dogs' weights, and find they have a mean weight of 48 ounces. Assume the population standard deviation is 11.9 ounces. Based on this, construct a 95% confidence interval for the true population mean dog weight.

Round your answers to two decimal places.

2) Given that x̄ = 33, n = 42, and σσ = 3, then we can be 95% confident that the true mean,μμ, lies between the values

Answer 1

Solution :

Given that,

1)

Sample size = n = 33

Z/2 = 1.96

Margin of error = E = Z/2* ( /n)

=1.96 * (11.9 / 33)

= 4.06

At 95% confidence interval estimate of the population mean is,

- E < < + E

48 - 4.06 < < 48 + 4.06

43.94 < < 52.06

(43.94 , 52.06)

2)

Sample size = n = 42

Z/2 = 1.96

Margin of error = E = Z/2* ( /n)

= 1.96 * (3 / 42)

= 0.91

At 95% confidence interval estimate of the population mean is,

- E < < + E

33 - 0.91 < < 33 + 0.91

32.09 < < 33.91

(32.09 , 33.91)