Two different age groups were surveyed about the amount of time they spent on social media.
+
The results are shown on the two frequency
polygons below. The same time intervals were
used for both graphs.
a) How many 18-year old
students took part in
12-year old students
18-year old students
80+
80+
the survey?
70
70
60
60
250
250
b) How many more 18-year
old students than 12-year
940
740
old students spent
30
.30
20
20
between 25 and 35 mins
on social media?
10
10
0
0
0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80

step-by-step explanation:

y=3n + 1

step-by-step explanation:

this is wrong because it says the second number is one less and i added one instead

step-by-step explanation:

i found the life tables for the year 2012. 

life table of males at age 30. probability of dying between ages x and x+1

total population:  

29–30 . . . . . . . . . . . . 0.001030

30–31 . . . . . . . . . . . . 0.001061

males:  

29–30 . . . . . . . . . . . . 0.001420

30–31 . . . . . . . . . . . . 0.001448

white population

29–30 . . . . . . . . . . . . 0.001005

30–31 . . . . . . . . . . . . 0.001037

white males

29–30 . . . . . . . . . . . . 0.001372

30–31 . . . . . . . . . . . . 0.001399

non hispanic white population

29–30 . . . . . . . . . . . . 0.001083

30–31 . . . . . . . . . . . . 0.001116

non hispanic white males

29–30 . . . . . . . . . . . . 0.001477

30–31 . . . . . . . . . . . . 0.001503

jacob, non hispanic white male. 30 years old.

probability that jacob lives to be 30 years old. 

since the given probabilities are probabilities of dying, i think we simply subtract it from 1 to get the probability of living. we will use the probability of non hispanic white male.

                                          probability of living to be 30 y.o.

29 - 30 : 1 - 0.001477 = 0.998523

30 - 31 : 1 - 0.001503 = 0.998497

13cm

step-by-step explanation:

(apex)