Answer:
<h2>2.5 hours</h2>
Step-by-step explanation:
Step one:
given data
for train one
speed= 50miles per hour
for train two
speed= 60miles per hour
the total distance between both trains=275miles
Step two:
the expression for speed= distance/time
so that, distance= speed*time
let the time be t
we are going to combine both distances
train one distance =50t
train two distance =60t
Hence total distance
50t+60t=275
110t=1=275
t=275/110
t=2.5 hours
<u>It will take 2.5 hours</u>
Answer:
Step-by-step explanation:
n = 400
Proportion p = 229/400= 0.5725
For 95% confidence interval we use Z value as 1.96
Std error = 0.025
margin of error = 1.96*0.025
Confidence interval 95% = 0.5725±Margin of error
= (0.524, 0.621)
b) When smiled x becomes 277
p = 0.6925
Std error = 0.023
Margin of error= 1.96*0.023
Confidence interval = (0.647, 0.738)
Smiling increases the chances of stopping since mean and conidence interval bounds are showing increasing trend.
Answer:

Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or 
we have the points (2,14) and (4,28)
Find out the constant of proportionality k
For (2,14) ----> 
For (4,28) ----> 
so
the value of
therefore
The equation is
(-1,10), (2,1) , (0,7), (-2,1)