AQA S3 2010 June — Question 2

Exam BoardAQA
ModuleS3 (Statistics 3)
Year2010
SessionJune
TopicLinear combinations of normal random variables
TypeTwo-sample t-test (unknown variances)

2 Rodney and Derrick, two independent fruit and vegetable market stallholders, sell punnets of locally-grown raspberries from their stalls during June and July. The following information, based on independent random samples, was collected as part of an investigation by Trading Standards Officers.
\cline { 3 - 5 } \multicolumn{2}{c|}{}Weight of raspberries in a punnet (grams)
\cline { 3 - 5 } \multicolumn{2}{c|}{}Sample sizeSample meanSample standard deviation, \(\boldsymbol { s }\)
\multirow{2}{*}{Stallholder}Rodney502255
\cline { 2 - 5 }Derrick752198
  1. Construct a \(99 \%\) confidence interval for the difference between the mean weight of raspberries in a punnet sold by Rodney and the mean weight of raspberries in a punnet sold by Derrick.
  2. What can be concluded from your confidence interval?
  3. In addition to weight, state one other factor that may influence whether customers buy raspberries from Rodney or from Derrick.
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