A batch of weighing machines has been purchased and one machine selected at random for testing. Ten weighing tests have been conducted and the errors found noted as follows;
Test: 1 2 3 4 S 6 7 8 9 10
Error (gms): 4.6 8.2 2.1 6.3 5.0 3.6 1.4 4.1 7.0 4.5
The purchasing manager has previously accepted machines with a mean error of 3.8gms and
asserts these tests are below standard. Test the assertion at 5% level. ​