Average speed is defined as the ratio of total distance covered in total given time

here we know that total distance that man moved is


so total distance is



now here total time of the motion is


total time will be given as


now by above formula


so his average speed is 30 km/h
Answer: 
Explanation:
The confidence interval for population mean is given by :-

Given : Sample size : 
Sample mean : 
Standard deviation : 
Significance level : 
Critical value : 
Now, the 95% confidence interval estimate of the (true, unknown) mean sound intensity of all food processors of this type :-

Answer:im so sorry i cant find anything either ask your teacher for some help is the best thing i can do
the force applied when using a simple machine is called the effort force