Answer:
b. between $3.04 and $3.36
Step-by-step explanation:
Given,
Price of 1 gallon of gasoline = $3.20
Margin of Error = 5%
We have to find out average cost of gallon of gasoline.
For this, we have to find out 5% of the price of gasoline. Which is calculated by dividing 5 by 100 and then multiply it by 3.20.
Amount of margin of error = 
Hence The margin of error is ±, So we will subtract the amount of margin of error with actual amount of 1 gallon of gasoline. Also we will add the amount of margin of error with actual amount of 1 gallon of gasoline.
Margin of error 1 = 
Margin of error 2 = 
Hence the Average cost of a gallon of gasoline should be between $3.04 and $3.36.
An=a1+d(n-1)
an=nth term
a1=first term, when n=1
d=common differnce=amount each term increases by
n=which one
so
when n=1, an=40
so a1=40
it seems to increas by 7 each time
an=40+7(n-1)
explicit formula is expanded
an=40+7n-7
an=33+7n is the formula
the domain is natural numbers because you can't have the -3rd term or the 0th term or the 3.24th term
domain is natural numbers
the formula is
or
Complete Question
A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20. What proportion of wand prices are lower than the price of the blackthorn wand? You may round your answer to four decimal places
Answer:
0.1151
Step-by-step explanation:
We solve using z score formula
z = (x-μ)/σ, where
x is the raw score = $45.20
μ is the population mean = $50
σ is the population standard deviation = $4
We are solving for x < 45.20
Hence:
z = 45.20 - 50/4
z = -1.2
Probability value from Z-Table:
P(x<45.20) = 0.11507
Approximately to 4 decimal places = 0.1151
Therefore, the proportion of wand prices that are lower than the price of the blackthorn wand is 0.1151
