The average wind speeds for one year at 44 climatic data centers around the united states are as follows:
9.0, 6.9, 9.1, 9.2, 10.2, 12.5, 12.0, 11.2, 12.9, 10.3, 10.6, 10.9, 8.7, 10.3, 10.6, 10.9, 8.7, 10.3, 11.0, 7.7, 11.4, 7.9, 9.6, 8.0, 10.7, 9.3, 7.9, 6.2, 8.3, 8.9, 9.3, 11.6, 10.6, 9.0, 8.2, 9.4, 10.6, 9.5, 6.3, 9.1, 7.9, 9.7, 8.8, 6.9, 8.7, 9.0, 8.9, 9.3

a) make a stem plot of the average wind speeds data. the frequency in the stem for 9 to 9.9 is?

b) the first quartile for the wind speed data set is?

The stem and leaf diagram is shown below

There are a total of 48 data

Question a:
The frequency in the stem for 9 to 9.9 is 13 data

Question b:
The location of the first quartile is given by , where 'n' is the number of data

We have n = 48

Location of the first quartile is at  rounded down to 12

The value of the lower quartile is on the  on the diagram which is 8.7

Candy >  contains 25% dark chocolate
so 
            > contains 75% milk chocolate > 3 pounds
X=the total number of pounds of dark chocolate and milk chocolate in the candy
a=number of pounds of dark chocolate
b=number of pounds of milk chocolate
X=a+b
a=X*0.25
b=X*0.75

X=X*0.25+b > X=(4/3)b

1) using one variable  b
the equation is  X=(4/3)b
b=number of pounds of milk chocolate

2) How many pounds of dark chocolate are present in the candy? 
X=(4/3)b > X=(4/3)*3=4 pounds is the total
X=4 pounds
b=3 pounds
a=X-b
pounds of dark chocolate=4-3=1 pound