At a medical center, a sample of 20 days showed the following number of cardiograms done each day.

25 31 20 32 13 14 43 12 57 23 36 32 33 32 44 32 52 44 51 46

(a) find the sample mean x.

(b) construct a stem and leaf plot for the data.

(c) find the sample variance s^2 and the sample standard deviation

a) 33.6

b)

Stem   Leaf

1      2 3 4

2     0 3 5

3     1 2 2 2 2 3 6

4     3 4 4 6

5     1 2 7

c)

Sample variance=174.57

Sample Standard deviation=13.21

Step-by-step explanation:

a) The sample mean xbar is computed by adding all x's values and divided the resultant value to number of observation

sumx=25+31+20+32+13+14+43+12+57+23+36+32+33+32+44+32+52+44+51+46

sumx=672

sample mean=672/20=33.6

b) Firstly arranging the data into ascending order

12,13,14,20,23,25,31,32,32,32,32,36,43,44,44,46,51,52

Now making stem and leaf plot

Stem   Leaf

1      2 3 4

2     0 3 5

3     1 2 2 2 2 3 6

4     3 4 4 6

5     1 2 7

The stems are 1,2,3,4 and 5. The leaves are 234,035,1222236,3446 and 127.

c)

Sample variance=174.57

Sample standard deviation=13.21

the number of the people going.

step-by-step explanation:

the cost to buy one movie ticket is $7. if the total cost for the movie is a function of how many people go, then the input is : the number of the people going.

- "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."