Answer:
a) Test statistic = 1.960
b) The critical values include -2.50 and 2.50.
The critical regions of rejection are thus
t < -2.50 or t > 2.50
c) The sketch of the curve is presented in the attached image to this solution. The shaded parents indicate the rejection regions.
d) The t-statistic obtained (1.96), lies within the acceptance region (-2.50 ≤ x ≤ 2.50), we fail to reject the null hypothesis.
Step-by-step explanation:
a) Test statistic is computed using the expression
t = (x - μ₀)/σₓ
x = Sample mean = 104.2
μ₀ = the standard we are comparing Against
σₓ = standard error of the mean = (σ/√n)
σ = 9.6
n = Sample size = 24
σₓ = (9.6/√24) =
t = (0.425 - 0.35) ÷ 0.07816
t = 1.9595917942 = 1.960
b) To obtain these critical values, we first find the degree of freedom
Degree of freedom = n - 1 = 24 - 1 = 23
The critical values for significance level of 0.01 and degree of freedom of 23 is given as
t(0.01, 23) = 2.50
So, since the test is two-tailled (we are testing in both directions; greater than or less than), the regions of rejection include
t < -2.50 and t > 2.50
c) since the test is two-tailled (we are testing in both directions; greater than or less than), the regions of rejection include
t < -2.50 and t > 2.50
The t-distribution curve is very similar to the normal distribution curve. The t-distribution curve is also a bell shaped curve, but it is heavier at the limits indicating that the t-distribution favours outliers more than the normal distribution.
The sketch of the curve is presented in the attached image with the shaded regions indicating the rejection region.
d) Since the t-statistic obtained (1.96), lies within the acceptance region (-2.50 ≤ x ≤ 2.50), we fail to reject the null hypothesis.
Hope this Helps!!!
