1. A group of Internet users 50-65 years of age were randomly chosen and asked to report the weekly number of hours they spend online. The purpose of the study was to determine whether the mean weekly number of hours that Internet users in that age group spend online differs from the mean for Internet users in general, which is 12.5 (as reported by "The Digital Future Report: Surveying the Digital Future, Year Four"). The following information is available:
Test of mu = 12.5 vs mu not = 12.5
Variable N Mean St. Dev SE Mean
hr. online 125 12.008 3.214 0.287
Variable 95.0% CI T P
hr. online (11. 439, ) -1.71 0.090
The population standard deviation is apparently:.
a. unknown
b. 3.214
c. 0.287
2. Note that the upper limit of the 95% confidence interval has been edited out. Which of the following is the number that has been edited out?
a. 12.375
b. 12.577
c. 13.439
3. If we suspected that the mean were less than 12.5, and carried out a one-sided test at the .05 significance level, we would conclude that the mean weekly number of hours that Internet users 50-65 years of age spend online:.
a. equals 12.5.
b. may equal 12.5.
c. is apparently different from 12.5.
d. is apparently less than 12.5.

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500

step-by-step explanation:

what are the statements? and what do you mean by "216 2 1 6"?

hello from mrbilldoesmath!

answer:   (7x + 6y) ( 49x^2 - 42xy + 36y^2)

discussion:

in general, the factorization of a^3 + b^3 is

a^3 + b^ 3 = (a + b) ( a^2 - ab + b^2)

in our case note that 343 = 7^3 and 216 = 6^3 so the equation becomes:

343x^3 + 216y^3 = (7x)^3 + (6y)^3

if you think of a (above) as 7x and b as 6y the factorization becomes

343x^3 + 216y^3 =

((7x + 6y) (   (7x)^2 - 7x*6y + (6y)^2)   =

(7x + 6y) ( 49x^2 - 42xy + 36y^2)

you,

mrb

(a + b) (a^2 - a b + b^2)