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3 years ago

Simplest form of 7/9 x 21/10

Mathematics

2 answers:

boyakko [2]3 years ago

5 0

7/9 times 21/10 can become 7/3 times 7/10 which is 49/30 which is 1 19/30 at it's most reduced form since 19 is prime.

gogolik [260]3 years ago

4 0

There’s app will help you every math problem

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You are driving due north on the highway. Ahead, but off to the East, you see a tall tower. Sketch a graph or make a table showi

valentina_108 [34]

Answer:

The amount of speed you go will determine the graph but it should go closer and closer but then farther away because you drive past the tower

Step-by-step explanation:

3 0

3 years ago

Solve the following proportion for x. 3/13 = x/5 Round your answer to the nearest tenth.

anastassius [24]

To solve, isolate the x. Cross multiply

3/13(13)(5) = x/5(5)(13)

3(5) = (13)x

Simplify

13x = 15

Isolate the x. Divide by 13.

13x/13 = 15/13

x = 15/13

x = 1.2

1.2 is your answer

hope this helps

8 0

3 years ago

A random sample of 20 students yielded a mean of ¯x = 72 and a variance of s2 = 16 for scores on a college placement test in mat

Helen [10]

Answer:

The 98% confidence interval for the variance in the pounds of impurities would be $8.400 \leq \sigma^2 \leq 39.827$ .

Step-by-step explanation:

1) Data given and notation

$s^2 =16$ represent the sample variance

s=4 represent the sample standard deviation

$\bar x$ represent the sample mean

n=20 the sample size

Confidence=98% or 0.98

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population mean or variance lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

The Chi square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

On this case the sample variance is given and for the sample deviation is just the square root of the sample variance.

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=20-1=19$

Since the Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical values.