Answer: c. 3.01
Step-by-step explanation:
The test statistic for difference between two population mean (when population standard deviation is known) is given by :

, where
= Size of first sample
= Size of second sample
= Difference between two sample mean.
= standard deviation for population 1.
= standard deviation for population 2.
As per given , we have



Substitute these values in formula , we get




Hence, the value of the test statistic is <u>3.01</u>.
Hence, the correct option is c. 3.01 .