Question

1. the national average price per gallon for gasoline is normally distributed with a mean (currently) of $2.34 per gallon with a standard deviation of $0.26 per gallon. what is the proportion of the gas prices that lie between $2.00 and $3.00? round to the nearest tenth.

Explanation:

Step1: Calculate z - score for 2.00

The formula for z - score is $z=\frac{x - \mu}{\sigma}$, where $x$ is the value, $\mu$ is the mean, and $\sigma$ is the standard deviation.
For $x = 2.00$, $\mu=2.34$, $\sigma = 0.26$:
$z_1=\frac{2.00 - 2.34}{0.26}=\frac{- 0.34}{0.26}\approx - 1.31$

Step2: Calculate z - score for 3.00

For $x = 3.00$, $\mu = 2.34$, $\sigma=0.26$:
$z_2=\frac{3.00 - 2.34}{0.26}=\frac{0.66}{0.26}\approx2.54$

Step3: Find the area between z - scores

We need to find $P(-1.31We know that $P(-1.31From the standard normal table:
$P(Z < 2.54)\approx0.9945$
$P(Z < - 1.31)\approx0.0951$
So, $P(-1.31

Answer:

0.9