Answer:
Hypothesis Test states that we will accept null hypothesis.
Step-by-step explanation:
We are given that an engineer is comparing voltages for two types of batteries (K and Q).
where,  = true mean voltage for type K batteries.
 = true mean voltage for type K batteries.
             = true mean voltage for type Q batteries.
 = true mean voltage for type Q batteries.
So, Null Hypothesis,  :
 :   {mean voltage for these two types of
 {mean voltage for these two types of
                                                         batteries is same}
Alternate Hypothesis,  :
 :  {mean voltage for these two types of
 {mean voltage for these two types of
                                                           batteries is different]
<em>The test statistics we use here will be :</em>
                       follows
  follows 
where,  = 8.54         and
 = 8.54         and      = 8.69
 = 8.69
                  = 0.225       and
  = 0.225       and          =  0.725
     =  0.725
                 =  37           and
   =  37           and          =  58
     =  58
                 =  0.585               Here, we use t test statistics because we know nothing about population standard deviations.
  =  0.585               Here, we use t test statistics because we know nothing about population standard deviations.
      Test statistics =   follows
 follows 
                              = -1.219
<em>At 0.1 or 10% level of significance t table gives a critical value between (-1.671,-1.658) to (1.671,1.658) at 93 degree of freedom. Since our test statistics is more than the critical table value of t as -1.219 > (-1.671,-1.658) so we have insufficient evidence to reject null hypothesis.</em>
Therefore, we conclude that mean voltage for these two types of batteries is same.