perimeter means to add up all the number around a surface so you are correct the answer is 12 because you are suppose to add up everything around the object so 7+5 which gives you 12
Answer: the z score is 1
Step-by-step explanation:
Since the head circumference for boys at birth is normally distributed,
we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = head circumference for boys at birth.
µ = mean head circumference
σ = standard deviation
From the information given,
µ = 34.5cm
σ = 1.3 cm
For a boy born with a head circumference of 35.8cm, the z score is
z = (35.8 - 34.5)/1.3
z = 1
Distance = 30 mph * time
distance = 4 mph * time
distance = 30 mph * t
distance = 4 mph * (17-t)
Since distance is equal then
30 mph * t = 4 mph * (17-t)
30t = -4t + 68
34t = 68
t = 2 hours
We see the return trip time is (17 -t ) which is 15 hours.
The beginning trip time is 2 hours.
Double Check
Beginning trip = 30 miles * 2 = 60 miles
Return trip = 4 miles * 15 = 60 miles.
4 and a half is 4.5, and if you divide 3 into that, you get 1.5.