College

Thank you for visiting You wish to test the following claim tex H a tex at a significance level of tex alpha 0 01 tex tex begin array l. This page is designed to guide you through key points and clear explanations related to the topic at hand. We aim to make your learning experience smooth, insightful, and informative. Dive in and discover the answers you're looking for!

You wish to test the following claim [tex]H_a[/tex] at a significance level of [tex]\alpha=0.01[/tex].

[tex]
\begin{array}{l}
H_0: \mu_1 = \mu_2 \\
H_a: \mu_1 \textless \mu_2
\end{array}
[/tex]

You obtain the following two samples of data.

**Sample #1**

[tex]
\begin{array}{|r|r|r|r|}
\hline
72 & 63.2 & 58.4 & 73.2 \\
\hline
62.7 & 69.2 & 76.6 & 73.5 \\
\hline
73.5 & 70.6 & 83 & 57.5 \\
\hline
86.9 & 78.4 & 77.5 & 70 \\
\hline
78.4 & 59.3 & 76.6 & 78.4 \\
\hline
82.6 & 74.5 & 94.2 & 69.6 \\
\hline
75.4 & 86.9 & 71.3 & 75.1 \\
\hline
77.5 & 59.3 & 96.2 & 71 \\
\hline
94.2 & 83.7 & 78.4 & 77.8 \\
\hline
67.4 & 71.6 & 99.1 & 97.5 \\
\hline
96.2 & 86.1 & 67 & 90.5 \\
\hline
65.2 & 51.4 & 66.5 & 91.1 \\
\hline
82.6 & 68.1 & 104.4 & 69.6 \\
\hline
66.5 & 97.5 & 85.2 & 91.8 \\
\hline
\end{array}
[/tex]

**Sample #2**

[tex]
\begin{array}{|r|r|r|r|}
\hline
62.9 & 64 & 96.5 & 105.8 \\
\hline
66.7 & 64.6 & 68.2 & 75.6 \\
\hline
97.3 & 59.5 & 71.4 & 69.6 \\
\hline
76 & 82.1 & 91.7 & 64 \\
\hline
74.3 & 78.8 & 68.7 & 71.8 \\
\hline
67.2 & 105.8 & 88 & 67.2 \\
\hline
75.6 & 64 & 85.6 & 77.2 \\
\hline
57 & 69.6 & 56 & 84.2 \\
\hline
79.6 & 85.6 & 72.7 & 64 \\
\hline
102.6 & 90.6 & 79.2 & 89 \\
\hline
100.2 & 88 & 93 & 76 \\
\hline
75.6 & 64 & 67.2 & 95.7 \\
\hline
59.5 & 56 & 95 & 88 \\
\hline
64 & 69.2 & 95.7 & 99.2 \\
\hline
74.3 & & & \\
\hline
\end{array}
[/tex]

1. What is the test statistic for this sample? (Report answer accurate to three decimal places.)
Test statistic [tex]= \square[/tex]

2. What is the [tex]p[/tex]-value for this sample? For this calculation, use the degrees of freedom reported from the technology you are using. (Report answer accurate to four decimal places.)
[tex]p[/tex]-value [tex]= \square[/tex]

The [tex]p[/tex]-value is...

Answer :

We wish to test

[tex]$$
\begin{aligned}
H_0 &: \mu_1 = \mu_2,\\[1mm]
H_a &: \mu_1 < \mu_2,
\end{aligned}
$$[/tex]

using data from two independent samples at a significance level of [tex]$\alpha = 0.01$[/tex].

The procedure is as follows:

1. Compute Sample Statistics.
For each sample, calculate the sample mean, denoted by [tex]$\bar{x}_1$[/tex] and [tex]$\bar{x}_2$[/tex], the sample variance [tex]$s_1^2$[/tex] and [tex]$s_2^2$[/tex], and note the sample sizes [tex]$n_1$[/tex] and [tex]$n_2$[/tex].

2. Welch’s Two-Sample [tex]$t$[/tex]‑Test.
Since we do not assume equal variances, we use Welch’s [tex]$t$[/tex]‑test. The test statistic is given by

[tex]$$
t = \frac{\bar{x}_1 - \bar{x}_2}{\sqrt{\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2}}}.
$$[/tex]

3. Degrees of Freedom.
The degrees of freedom for Welch’s test are approximated by the Welch–Satterthwaite equation:

[tex]$$
df = \frac{\left(\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2}\right)^2}{\frac{\left(\frac{s_1^2}{n_1}\right)^2}{n_1-1} + \frac{\left(\frac{s_2^2}{n_2}\right)^2}{n_2-1}}.
$$[/tex]

4. One-Tailed [tex]$p$[/tex]-Value.
The two-sample [tex]$t$[/tex]‑test typically provides a two-tailed [tex]$p$[/tex]‑value. Since our alternative hypothesis is [tex]$H_a: \mu_1 < \mu_2$[/tex], we adjust the two-tailed [tex]$p$[/tex]‑value to obtain a one-tailed [tex]$p$[/tex]‑value. In this case, if the test statistic is negative then the one-tailed [tex]$p$[/tex]‑value is half of the two-tailed value.

After performing the necessary calculations from the sample data, the computed values (rounded as requested) are:

- The test statistic is

[tex]$$
t \approx -0.229.
$$[/tex]

- The corresponding one-tailed [tex]$p$[/tex]‑value is

[tex]$$
p \approx 0.4097.
$$[/tex]

Since the [tex]$p$[/tex]-value is quite high, we do not reject [tex]$H_0$[/tex] at the [tex]$\alpha=0.01$[/tex] level.

Thus, the final answers are:

Test statistic [tex]$=$[/tex] [tex]$-0.229$[/tex]

[tex]$p$[/tex]-value [tex]$=$[/tex] [tex]$0.4097$[/tex]

The [tex]$p$[/tex]-value is greater than [tex]$\alpha = 0.01$[/tex], indicating that there is not enough evidence to support the claim that [tex]$\mu_1 < \mu_2$[/tex].

Thank you for reading the article You wish to test the following claim tex H a tex at a significance level of tex alpha 0 01 tex tex begin array l. We hope the information provided is useful and helps you understand this topic better. Feel free to explore more helpful content on our website!

Rewritten by : Jeany