How do you subtract fractions when there's a negative

HELP

SVEN [57.7K]

Answer:

It's Tan.

Multiple Thumbs-up ^_^

5 0

3 years ago

Michael baked 60 oatmeal cookies and 45 chocolate chip cookies to package in plastic containers for her friends at school. She w

Scrat [10]

Answer:

3

Step-by-step explanation:

Michael must find the smallest number possible that can divide 60 and 45 then take the two quotients after dividing the 2 types of cookies by the smallest number possible.

2 is not possible as 45 is an odd number

3 can divide both 60 and 45

60/3 = 20 oatmeal cookies in each container.

45/3 = 15 chocolate chip cookies in each container.

7 0

2 years ago

If 9% of the bar’s weight is iron, how much does the iron weigh

Leya [2.2K]

Answer:

15 pounds

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Janice thinks that 20 hundredths is equivalent to 2 thousandths because 20 hundreds is equal to 2 thousands. Use words and a pla

Anna [14]

1 hundredth is equal to 0.01 therefore 20 hundredths is equal to 0.2. 1 thousandth is equal to 0.001 therefore 2 thousandths is equal to 0.002. Clearly these are not equivalent.
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6 0

3 years ago

A television station plans to ask a random sample of 400 city residents if they can name the news anchor on the evening news at

hodyreva [135]

Answer:

There is an 8.38% probability that the anchor will be fired.

Step-by-step explanation:

For each resident, there is only two possible outcomes. Either they can name the news anchor on the evening news at their station, or they cannot.

This means that the binomial probability distribution will be used in our solution.

However, we are working with samples that are considerably big. So i am going to aaproximate this binomial distribution to the normal.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

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.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X), \sigma = \sqrt{V(X)}$ .

In this problem, we have that:

400 city residents are going to be asked. So $n = 400$ .

Suppose that in fact 12% of city residents could name the anchor if asked. This means that $p = 0.12$ .

So,

$\mu = E(X) = 400*0.12 = 48$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{400*0.12*0.88} = 6.5$ .

They plan to fire the news anchor if fewer than 10% of the residents in the sample can do so.

What is the approximate probability that the anchor will be fired?

10% of the residents is 0.10*400 = 40 residents.

Fewer than 10% is 39 residents. So the probability that the anchor will be fired is the pvalue of Z when $X = 39$ .

So:

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

$Z = \frac{39 - 48}{6.5}$

$Z = -1.38$

$Z = -1.38$ has a pvalue of 0.0838. This means that there is an 8.38% probability that the anchor will be fired.

5 0

3 years ago