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3 years ago

Matt is showing his work in simplifying (6.2 − 1.6) − 4.4 + 7.8. Identify any error in his work or reasoning.

Mathematics

1 answer:

goblinko [34]3 years ago

7 0

It should've been:
(6.2-1.6)-4.4+7.8
6,2-1.6-4.4+7.8=4.6-4.4+7.8=0.2+7.8=8

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. How many digits are there in the repeating block for the decimal equivalent of 3/7?

posledela

Answer:

42857142857

Step-by-step explanation:

3/7 = 0.42857142857...

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3 years ago

Geometry Question: BK bisects angle ABC and M angle ABK=28.3 degrees. Find M angle KBC and M angle ABC.

GarryVolchara [31]

Answer:

$KBC = 28.3$

$ABC = 56.6$

Step-by-step explanation:

Given

$ABK = 28.3$

Required

Determine KBC and ABC

Since BK bisects ABK, then

$KBC = ABK$

Substitute 28.3 for ABK

$KBC = 28.3$

Using same point as above

Since BK bisects ABK, then

$ABC = ABK + KBC$

$ABC = 28.3 + 28.3$

$ABC = 56.6$

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3 years ago

Reduce the fractions 12/5

Tresset [83]

If you reduce the fraction to a mixed number than it would be 2 2/5 but if you want to reduce it to a decimal it would be 2.4

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3 years ago

Read 2 more answers

Noise levels at 3 airports were measured in decibels yielding the following data:

Shalnov [3]

Answer:

a) The 90% confidence interval for the mean noise level at such locations

(112.46 , 163.54)

b) The critical value that should be used in constructing the confidence interval

Z₀.₁₀ = 1.645

Step-by-step explanation:

Step(i) :-

Noise levels at 3 airports were measured in decibels yielding the following data

108 146 160

Mean of given data

$x^{-} = \frac{108+146+160}{3} = 138$

x : 108 146 160

x-x⁻ : -30 8 22

(x-x⁻ )² : 900 64 484

Variance σ ² = ∑(x-x⁻ )²/ n-1

= $\frac{900+64+484}{3-1}= 724$

Standard deviation

σ = √724 = 26.90

Step(ii):-

The 90% confidence interval for the mean noise level at such locations

$(x^{-} - Z_{0.90} \frac{S.D}{\sqrt{n} } , (x^{-} + Z_{0.90} \frac{S.D}{\sqrt{n} } )$

The critical value that should be used in constructing the confidence interval

Z₀.₁₀ = 1.645

$(138 - 1.645 \frac{26.90}{\sqrt{3} } , (138 + 1.645 \frac{26.90}{\sqrt{3} } )$

( 138 - 25.54 , 138 + 25.54 )

(112.46 , 163.54)

4 0

3 years ago

An automobile manufacturer claims that its van has a 39.0 miles/gallon (MPG) rating. An independent testing firm has been contra

Nikolay [14]

Answer:

(1) H0: The mean MPG rating of the vans is 38.8

H1: The mean MPG rating of the vans is not 38.8

(2) The significance level is 2%

(3) The test statistic is -1

(4) The test is two tailed

(5) Fail to reject H0. The mean MPG rating of the vans is 38.8

Step-by-step explanation:

(1) A null hypothesis is a statement from a population parameter which is either rejected or accepted (fail to reject) upon testing.

An alternate hypothesis is also a statement from the population parameter that negates the null hypothesis and is accepted if the null hypothesis is rejected.

(2) The level of significance is 0.02 (2%)

(3) Z = (sample mean - population mean) ÷ sd/√n

sample mean = 38.8, population mean = 39, sd = 2.2, n = 120

Z = (38.8 - 39) ÷ 2.2/√120 = -0.2 ÷ 0.2 = -1

(4) A two tailed test is identified by the inequality not equal to.

(5) P-value = 1 - cumulative area of the test statistic = 1 - 0.8413 = 0.1587

(6) Fail to reject H0 because the P-value (0.1587) is greater than the significance level (0.02).

6 0

3 years ago