To determine the cost of each item, we need to set up equations. From the problem statement, we have three unknowns so we need three equations. We set up equations as follows:
let x cost of small pizzas
y cost of soda
z cost of salad
two small pizzas, a liter of soda, and a salad cost $14
2x + y + z = 14
one small pizza, a liter of soda, and three salads cost $15
x + y + 3z = 15
three small pizzas, a liter of soda, and two salads cost $22
3x + y + 2z = 22
Solving for x, y and z, we will have:
x = $ 5
y = $ 1
z = $ 3
Using the Empirical Rule, it is found that her finishing time will be between 70 and 82 seconds in 95% of her races.
<h3>What does the Empirical Rule state?</h3>
It states that, for a normally distributed random variable:
- Approximately 68% of the measures are within 1 standard deviation of the mean.
- Approximately 95% of the measures are within 2 standard deviations of the mean.
- Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, the mean is of 76 seconds and the standard deviation is of 3 seconds, then:
76 - 2 x 3 = 70.
76 + 2 x 3 = 82.
Which means that values between 70 and 82 seconds are within 2 standard deviations of the mean, hence the percentage is of 95%.
More can be learned about the Empirical Rule at brainly.com/question/24537145
Correct Question:
Otero translated the phrase "three less than a number" into the expression 3 minus x. Which best describes the accuracy of Otero's expression?.
a. It is accurate. The phrase can be translated as "three" = 3, "less than" = subtraction, and "a number" = X, SO 3- X is
the correct expression.
b. It is inaccurate. Three is being subtracted from a number, so X-3 is what he should have written.
c. It is inaccurate. Three is being compared to a number, so 3 It is inaccurate. Three is being added to a number, so 3+ x is what he should have written.
Answer:
The answer is B because three less than a number means that a 3 is less than some number X meaning three is being subtracted from X. So equation should be X-3 rather than 3-X.
Step-by-step explanation:
