On the planet of Mercury, 4-year-olds average 2.8 hours a day unsupervised. Most of the unsupervised children live in rural areas, considered safe. Suppose that the standard deviation is 1.4
hours and the amount of time spent alone is normally distributed. We randomly survey one Mercurian 4-year-old living in a rural area. We are interested in the amount of time X the child spends alone per day. (Source: San Jose Mercury News) Round all answers to 4 decimal places where possible.

a. What is the distribution of X? X-N( , )

b. Find the probability that the child spends less than 1.8 hours per day unsupervised.

c. What percent of the children spend over 2.5 hours per day unsupervised. [] %
Round to 2 decimal places)

d. 67% of all children spend at least how many hours per day unsupervised? hours. []

what is the graph

step-by-step explanation:

can you put the picture up?

step-by-step explanation:

unless you made a typo, the answers are both a and c.

step-by-step explanation:

1.5/3 is .5 whereas 3/9 is .3333333 not proportional

22/33 is .66666 and 4/6 is also .66666 proportional

2/4 is .5 whereas 142/213 is .66666 not proportional

14/7 is 2 and 7/3.5 is also 2 proportional

you could've also checked it by doing this simple division:

if the larger fraction divides with the smaller fraction to equal 1, it is proportional. so let me show you what i mean:

when i divide 22/33 by 4/6 i get 1, so we know it is proportional, and it is the same with 14/7 and 7/3.5. now if i divide 3/9 by 1.5/3 i get .66666 so therefore we know it is not proportional.

there are many ways to do this so i wanted to show you some possible ways.

question: use the following table of a school bus during morning pickups to calculate its average speed between 2.8 km and 4.2 km

answer: 42 km/h

explanation: 1.4/0.033 42.42424 = 42 km/h

question answered by

(jacemorris04)