A waitress believes the distribution of her tips has a model that is slightly skewed to the left, with a mean of $8.30 and a standard deviation of $4.70. She usually waits on about 60 parties over a weekend of work. a) Estimate the probability that she will earn at least $550.

probability = 0.9286

Step-by-step explanation:

given data

mean = $8.30

standard deviation = $4.70

waits parties over a weekend of work =  60

solution

when we earn at least $550 in 60 parties

so average per party will be x =

average x = 9.1667

so  now we get here z value that is

    ...............1

put here value and we get

z =    

z = 0.184404

so  

P(x>9.1667) = P(z>0.184404)

use standard normal table

probability = 1 - 0.0714 = 0.9286

where are the options?

step-by-step explanation:

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."