Answer:
P(X<1200) is 0.8212
Step-by-step explanation:
Test statistic (z) = (X - mean)/sd
X is score of a tester = 1200
mean = 1497
sd = 322
z = (1200 - 1497)/322 = -297/322 = -0.92
The cumulative area of the test statistic is the probability that X<1200. The cumulative area is 0.8212.
Therefore, P(X<1200) = 0.8212
<span>Kevin is 16
Timothy is 10
------------
check:
4 yrs ago Kevin was 12
4 yrs ago Timothy was 6
Kevin was twice his age
OK</span>
1/2 z = -3/4 + 1/4 z
1/2 z - 1/4 z = -3/4
1/4 z = -3/4
z = (-3/4)/(1/4)
z = -3/4 x 4/1
z = -3
Answer:
<h2> 3hours 55 minute</h2>
Step-by-step explanation:
Step one:
Given data
distance= 160miles
velocity = 3/4 miles per minutes
Step two:
Required:
time
we know that velocity is
v=distance/time
times= distance/velocity
time=160/3/4
time= 160*4/3
time=640/3
time=213.33333minuts
Time= 3hours 55 minute
