The amount of time required to reach a customer service representative has a huge impact on customer satisfaction. Below is the Excel output from a study to see whether there is evidence of a difference in the mean amounts of time required to reach a customer service representative between two hotels. Assume that the population variances in the amount of time for the two hotels are not equal.


t-Test: Two-sample assuming Unequal Variances

Hotel 1 Hotel 2
Mean 2.56 2.01
Variance 2.952 3.579
Observations 20 20
df 38
t Stat ?
t Critical one-tail 1.686
t Critical two-tail 2.024

Required:
What is the value of the test statistic?

Respuesta :

Answer:

The value of the test statistic is t=1.12.

Step-by-step explanation:

This is a hypothesis test for the difference between populations means.

The claim is that the mean amount of time required to reach a customer service representative significantly differs between the two hotels.

Then, the null and alternative hypothesis are:

[tex]H_0: \mu_1-\mu_2=0\\\\H_a:\mu_1-\mu_2\neq 0[/tex]

The sample 1, of size n1=20 has a mean of 2.65 and a standard deviation of √2.952=1.72.

The sample 2, of size n2=20 has a mean of 2.01 and a standard deviation of √2.952=1.89.

The difference between sample means is Md=0.64.

[tex]M_d=M_1-M_2=2.65-2.01=0.64[/tex]

The estimated standard error of the difference between means is computed using the formula:

[tex]s_{M_d}=\sqrt{\dfrac{\sigma_1^2+\sigma_2^2}{n}}=\sqrt{\dfrac{1.72^2+1.89^2}{20}}\\\\\\s_{M_d}=\sqrt{\dfrac{6.531}{20}}=\sqrt{0.327}=0.571[/tex]

Then, we can calculate the t-statistic as:

[tex]t=\dfrac{M_d-(\mu_1-\mu_2)}{s_{M_d}}=\dfrac{0.64-0}{0.571}=\dfrac{0.64}{0.571}=1.12[/tex]

The test statistics (t-statistic) value will be:

"1.12".

Mean and Standard deviation

According to the question,

The null and alternative hypothesis will be:

[tex]H_0[/tex] : μ₁ - μ₂ = 0

[tex]H_a[/tex] : μ₁ - μ₂ [tex]\neq[/tex] 0

Mean = 2.65 and 1.01

Observations = n₁ = n₂ = 20

Now,

The difference between sample mean.

→ [tex]M_d[/tex] = M₁ - M₂

        = 2.65 - 2.01

        = 0.64

The estimated standard error will be:

→ [tex]s_M_d[/tex] = [tex]\sqrt{\frac{\sigma_1^2 + \sigma_2^2}{n} }[/tex]

By substituting the values,

         = [tex]\sqrt{\frac{(1.72)^2 + (1.89)^2}{20} }[/tex]

         = [tex]\sqrt{\frac{6.531}{20} }[/tex]

         = [tex]\sqrt{0.327}[/tex]

         = 0.571

hence,

The test statistic (t) be:

= [tex]\frac{M_d(\mu_1 -\mu_2)}{s_M_d}[/tex]

= [tex]\frac{0.64-0}{0.571}[/tex]

= [tex]\frac{0.64-0}{0.571}[/tex]

= 1.12

Thus the above approach is right.

Find out more information about mean here:

https://brainly.com/question/4583894

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