All solutions here are SUGGESTED. Mr. Teng will hold no liability for any errors. Comments are entirely personal opinions.

(i)

Under

For to be not rejected at 5% level of significance, then

(ii)

Under

From the graphing calculator, p-value , we reject .

Thus, there is sufficient evidence at 5% level of significant to conclude that the mean salt content has been reduced.

### KS Comments

Read carefully that it is two-tailed and perform the test. Bare in mind to leave answers in set notation.

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