Questions: Choose the formula that is used to find the test statistic for a mean when the population standard deviation is unknown.
t = (x̄ - μ) / (s / √n)
z = (x̄ - μ) / (θ / √n)
z = (x̄ c - μ1) / (b / √n)
z = (χ - μ) / σ
Transcript text: Choose the formula that is used to find the test statistic for a mean when the population standard deviation is unknown.
$\mathrm{t}=\frac{\overline{\mathrm{x}}-\mu}{\frac{\mathrm{s}}{\sqrt{n}}}$
$\mathrm{z}=\frac{\overline{\bar{x}}-\mu}{\frac{\theta}{\sqrt{n}}}$
$z=\frac{\bar{x} c-\mu 1}{\frac{b}{\sqrt{n}}}$
$\mathrm{z}=\frac{\chi-\mu}{\sigma}$
Solution
Solution Steps
Step 1: Calculate the Standard Error
The standard error \( SE \) is calculated using the formula:
\[
SE = \frac{s}{\sqrt{n}} = \frac{10}{\sqrt{30}} \approx 1.8257
\]
Step 2: Calculate the Test Statistic
The test statistic \( t \) is calculated using the formula: