When using fraction strips how do you know that two fractions are equivelent

1 answer:

7 0

Fraction strips are mathematical manipulatives: objects that students can touch, feel and move around in order to learn mathematical concepts. Fraction strips are pieces of paper cut in various sizes to show the fraction's relationship to the whole unit. For example, a set of three 1/3 fraction strips placed side by side would make one whole unit. If you make or buy sets of fraction strips that are based on units of the same size, you can compare the strips representing different fractions.

You might be interested in

Somebody please help. And be fr cause I’ll give that brainilest or whatever it’s called but please be the right answer.

bearhunter [10]

130 you multiply the left side by 13 to get the right side.

8 0

3 years ago

Suppose that you are in charge of evaluating teacher performance at a large elementary school. One tool you have for this evalua

Strike441 [17]

Answer:

a) Standard error = 2

b) Range = (76.08, 83.92)

c) P=0.69

d) Smaller

e) Greater

Step-by-step explanation:

a) When we have a sample taken out of the population, the standard error of the mean is calculated as:

$\sigma_m=\dfrac{\sigma}{\sqrt{n}}=\dfrac{10}{\sqrt{25}}=\dfrac{10}{5}=2$

where n is te sample size (n=25) and σ is the population standard deviation (σ=10).

Then, the standard error of the classroom average score is 2.

b) The calculations for this range are the same that for the confidence interval, with the difference that we know the population mean.

The population standard deviation is know and is σ=10.

The population mean is M=80.

The sample size is N=25.

The standard error of the mean is σM=2.

The z-value for a 95% confidence interval is z=1.96.

The margin of error (MOE) can be calculated as:

$MOE=z\cdot \sigma_M=1.96 \cdot 2=3.92$

Then, the lower and upper bounds of the confidence interval are:

$LL=M-t \cdot s_M = 80-3.92=76.08\\\\UL=M+t \cdot s_M = 80+3.92=83.92$

The range that we expect the average classroom test score to fall 95% of the time is (76.08, 83.92).

c) We can calculate this by calculating the z-score of X=79.

$z=\dfrac{X-\mu}{\sigma}=\dfrac{79-80}{2}=\dfrac{-1}{2}=-0.5$

Then, the probability of getting a average score of 79 or higher is:

$P(X>79)=P(z>-0.5)=0.69146$

The approximate probability that a classroom will have an average test score of 79 or higher is 0.69.

d) If the sample is smaller, the standard error is bigger (as the square root of the sample size is in the denominator), so the spread of the probability distribution is more. This results then in a smaller probability for any range.

e) If the population standard deviation is smaller, the standard error for the sample (the classroom) become smaller too. This means that the values are more concentrated around the mean (less spread). This results in a higher probability for every range that include the mean.

6 0

3 years ago

The vertex of the function is (6, -8)

kolbaska11 [484]

Answer: I did a screen shot of the answer

Step-by-step explanation: