C) a researcher has extracted two samples from the same target population, sample a and sample b. sample a has a mean of 25 kg while sample b has a mean twice that of sample a. sample size of sample a is three times more than that of sample b. sum of sample sizes is 60. calculate:
i. mean of sample b (1mark)
ii. sample size of sample a and sample b (2 marks)
iii. summation of x variables for sample a and sample b (4 marks)
iv. standard deviation of sample a and sample b, consider ungrouped data (5 marks)

The avenues in a particular city run north to south and are numbered consecutively with 1st avenue at the western border of the city. the streets in the city run east to west and are numbered consecutively with 1st street at the southern border of the city. for a festival, the city is not allowing cars to park in a rectangular region bordered by 5th avenue to the west. 9th avenue to the east, 4th street to the south, and 6th street to the north. if x is the avenue number and yis the street number, which of the following systems describes the region in which cars are not allowed to park? 5th ave 9th ave