What is 3.45 written as a percentage?

Casey can buy 3 sandwiches and 5 cups of coffee for $26. Eric can buy 4 sandwiches and 2 cups of coffee for $23. How much does o

dolphi86 [110]

Let's identify what we are looking for in terms of variables. Sandwiches are s and coffee is c. Casey buys 3 sandwiches, which is represented then by 3s, and 5 cups of coffee, which is represented by 5c. Those all put together on one bill comes to 26. So Casey's equation for his purchases is 3s + 5c = 26. Eric buys 4 sandwiches, 4s, and 2 cups of coffee, 2c, and his total purchase was 23. Eric's equation for his purchases then is 4s + 2c = 23. In order to solve for c, the cost of a cup of coffee, we need to multiply both of those bolded equations by some factor to eliminate the s's. The coefficients on the s terms are 4 and 3. 4 and 3 both go into 12 evenly, so we will multiply the first bolded equation by 4 and the second one by -3 so the s terms cancel out. 4[3s + 5c = 26] means that 12s + 20c = 104. Multiplying the second bolded equation by -3: -3[4s + 2c = 23] means that -12s - 6c = -69. The s terms cancel because 12s - 12s = 0s. We are left with a system of equations that just contain one unknown now, which is c, what we are looking to solve for. 20c = 104 and -6c = -69. Adding those together by the method of elimination (which is what we've been doing all this time), 14c = 35. That means that c = 2.5 and a cup of coffee is $2.50. There you go!

8 0

2 years ago

A random sample of 625 10-ounce cans of fruit nectar is drawn from among all cans produced in a run. Prior experience has shown

diamong [38]

Answer:

10.57% probability that the mean contents of the 625 sample cans is less than 9.995 ounces.

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $\frac{\sigma}{\sqrt{n}}$ .

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 10, \sigma = 0.1, n = 625, s = \frac{0.1}{\sqrt{625}} = 0.004$

What is the probability that the mean contents of the 625 sample cans is less than 9.995 ounces?

This is the pvalue of Z when X = 9.995. So

$Z = \frac{X - \mu}{s}$

$Z = \frac{9.995 - 10}{0.004}$

$Z = -1.25$

$Z = -1.25$ has a pvalue of 0.1057

So there is a 10.57% probability that the mean contents of the 625 sample cans is less than 9.995 ounces.

5 0

2 years ago

How is shading a grid to show 1/10 different than 1/100

gayaneshka [121]

They are very different 1/10 is equivalent to 10% and also 0.1 but 1/100 is equivalent to 1% and 0.01

7 0

3 years ago

Find the value of (-64)2/3

Marizza181 [45]

Answer:

-42.66666...

Step-by-step explanation:

-64 * 2/3 is -42.66666...

well, according to the calculator.

7 0

3 years ago

Read 2 more answers

The ratio of clown fish to angel fish at a pet store is 5:4 . The ratio of angel fish to gold fish is 4:3. There are 60 clown fi

SVEN [57.7K]

A) 60 Clown fish / 5 = 12
12 x 4 = 28 Angel fish
B) 28 Angel fish / 4 = 12
12 x 3 = 36 Gold fish
C) Add all fish 28 Angel fish + 36 Gold fish + 60 Clown fish = 124 Fish in total

4 0

2 years ago