In order to determine whether or not there is a significant difference between the mean hourly wages paid by two companies (of the same industry), the following data have been accumulated. Company A Company B Sample size 80 60 Sample mean $16.75 $16.25 Population standard deviation $1.00 $.95 The p-value is a. .0084. b. .0042. c. .0026. d. .0013

Respuesta :

Answer:

The correct option is C

Step-by-step explanation:

From the question we are told that

    The  sample size for company A is [tex]n_1 = 80[/tex]

    The sample size for company B is  [tex]n_2 =  60[/tex]

    The sample mean for A is  [tex]\= x _1  = \$16.75[/tex]

    The sample mean for B  is  [tex]\= x _2  =  $16.25[/tex]

  The population standard deviation for A is  [tex]\sigma_1 =  \$1.00[/tex]

   The population standard deviation for B is   [tex]\sigma_1 = \$ 0.95[/tex]

The null hypothesis is  [tex]H_o :  \mu_1 - \mu_2 = 0[/tex]

The null hypothesis is  [tex]H_o :  \mu_1 - \mu_2 \ne 0[/tex]

Generally the test statistics is mathematically represented as

  [tex] z =  \frac{ \= x_1 - \= x_2}{ \sqrt{\frac{ \sigma_1^2}{n_1} + \frac{ \sigma_2^2}{n_2} } }[/tex]

=>   [tex]z  =  \frac{ 16.75 - 16.25}{ \sqrt{\frac{ 1.00^2}{80} + \frac{ 0.95^2}{60} } }[/tex]

=>   [tex]z  =  3.01283186 [/tex]

Generally from the  normal distribution table the probability  of  z  

      [tex]P(t > z) = 0.0013 [/tex]

Gnerally the p-value is mathematically represented as

     [tex]p-value  =  2 *  P(z > 3.0 )[/tex]

=>  [tex]p-value  =  2 *  0.0013 [/tex]

=>  [tex]p-value  =  0.0026 [/tex]