Answer:
and this Z-score is “unusual.”
Step-by-step explanation:
To calculate the Z score use the following formula

Where
μ is the average
is the standard deviation
x is the data to which we will calculate the z-score
In this case

So


A z-score is unusual if
or 
Finally
and this Z-score is “unusual.”
-10, -8, 0 and 2
Hope this helps! ;)
Answer:
5 miles per hour
Step-by-step explanation:
Let the speed of Kelly is
miles per hour and speed of Raul is v₂ miles per hour.
Since, speed = 
Kelly took 135 minutes to cover 90 miles from New York to Philadelphia.
∵ 1 minute =
hours
∴ 135 minutes =
=
hours
v₁ = 
= 
= 40 miles per hour
Raul took 153 minutes to cover the same distance as Kelly,
∵ 1 minute =
hours
∴ 153 minutes =
=
hours
v₂ = 
= 35.29
≈ 35.3 miles per hours
v₁ - v₂ = 40 - 35.3
= 4.7
≈ 5.0 miles per hours
Therefore, Kelly is 5 miles per hours faster than Raul.
1
The exact value of tan(π4) tan ( π 4 ) is 1 .