This data can be modelled by the regression line with equation V �aW � b .
( d ) ( i ) Write down the value of a and of b .
( ii ) Explain what the gradient a represents .
[ 3 ]
The reporter in the interview would like to verify whether Alex ’ s claim about the mean weight of the crabs is correct . Later , fifteen crabs are randomly selected to form a sample such that the sample mean weight is 297 grams . It is given that the population standard deviation is 10 grams in the hypothesis test conducted at a 10 % significance level .
( e ) ( i ) Write down the null hypothesis of the test .
( ii ) Write down the alternative hypothesis of the test .
( iii ) Write down the test statistic z .
( iv ) Find the p -value .
( v ) State the conclusion of the test with a reason . [ 7 ]
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