Answer:
D
Step-by-step explanation:
it's 100% I'm super sure
Let <em>X</em> be the random variable representing the amount (in grams) of nicotine contained in a randomly chosen cigarette.
P(<em>X</em> ≤ 0.37) = P((<em>X</em> - 0.954)/0.292 ≤ (0.37 - 0.954)/0.292) = P(<em>Z</em> ≤ -2)
where <em>Z</em> follows the standard normal distribution with mean 0 and standard deviation 1. (We just transform <em>X</em> to <em>Z</em> using the rule <em>Z</em> = (<em>X</em> - mean(<em>X</em>))/sd(<em>X</em>).)
Given the required precision for this probability, you should consult a calculator or appropriate <em>z</em>-score table. You would find that
P(<em>Z</em> ≤ -2) ≈ 0.0228
You can also estimate this probabilty using the empirical or 68-95-99.7 rule, which says that approximately 95% of any normal distribution lies within 2 standard deviations of the mean. This is to say,
P(-2 ≤ <em>Z</em> ≤ 2) ≈ 0.95
which means
P(<em>Z</em> ≤ -2 or <em>Z</em> ≥ 2) ≈ 1 - 0.95 = 0.05
The normal distribution is symmetric, so this means
P(<em>Z</em> ≤ -2) ≈ 1/2 × 0.05 = 0.025
which is indeed pretty close to what we found earlier.
Answer:
<em>Daniel does have enough money to make this car payment</em>
Step-by-step explanation:
<u>Addition and Subtraction</u>
Daniel has an initial balance of $460.63 on this checking account.
He must pay $85.23 for groceries.
The new balance is $460.63 - $85.23 = $375.40
He then pays $81.34 for his cell phone bill. The balance is now $375.40 - $81.34 = $294.06.
He receives a shopping refund of $52.13 that adds up to this balance that now is: $294.06 + $52.13 = $346.19.
Daniel has to make his $264 car payment. The balance is $346.19, thus:
Daniel does have enough money to make this car payment
