The signal strengths, measured in decibel-milliwatts (dBm), were recorded for two competing IoT transmission protocols within a smart city grid. A random sample of 80 transmission points using Protocol X yielded a mean signal strength of −53.2-53.2−53.2 dBm with a standard deviation of 3.83.83.8 dBm. A second independent random sample of 120 transmission points using Protocol Y yielded a mean signal strength of −51.5-51.5−51.5 dBm with a standard deviation of 4.64.64.6 dBm.
Test, at the 1% level of significance, whether the mean signal strength of Protocol X is lower than the mean signal strength of Protocol Y. State your hypotheses clearly.
State two assumptions required for the validity of the hypothesis test performed in part (a).
Practise Edexcel A Level Maths The Normal Distribution with exam-style questions for A Level Maths. 439 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.