Answer: a = -2/3
Step-by-step explanation:
Let's start by multiplying both sides by
to simplify:




Looking only at the exponents, it seems like
, so
.
Answer: 1. 2262
Step-by-step explanation:
Answer:
0.173 probability that she gets exactly three questions correct.
Step-by-step explanation:
For each question, there are only two possible outcomes. Either she guesses the correct answer, or she does not. The probability of guessing the correct answer for a question is independent of other questions. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
Seven questions:
This means that 
Each question has four choices.
Abby guesses, which means that 
Find the probability to the nearest thousandth, that Abby gets exactly three questions correct.
This is P(X = 3).


Answer:
9 square kilometers
Step-by-step explanation:
Let's round the width to 2.0 kilometers, and round the length to 4.5 kilometers.
We know that area is length times width, so
A = lw
A = 2.0*4.5
<u>A = 9.0 square kilometers</u>
If we do this on the calculator, it's around 9.36 square kilometers, so our estimate was good.