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3 years ago

HELP ME PLEASE I NEED HELP

Mathematics

1 answer:

Vladimir79 [104]3 years ago

5 0

Answer:

1. 3-5

2. 5-3

3. 3-5

4. 5-3

Step-by-step explanation:

This is simple! Just get rid of the parenthesis for each of the expressions shown.

3 + (-5)

the plus sign is next to the negative which is in the parenthesis. Negative times positive is equal to negative. The expression then becomes

3 - 5

Now do the same for the rest!

For things like 3 and 4, you can just flip it like 3-5 and 5-3 because it will all equal the same :]

Hope this helps !!

-Ketifa

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The size of each interior angle of a regular polygon is 156 degrees. Work out the number of sides the polygon has.

stira [4]

$\alpha = \frac{n-2}{n} \cdot 180 \ \ \ \ \ \ \ [\alpha =interior\ angle, \ n=number \ of \ sides] \\ \\ 156=\frac{n-2}{n} \cdot 180 \\ 156n=(n-2)180 \\ 156n = 180n - 360 \\ 360 = 180n-156n \\ 360 = 24n \\ n=360/24=15$

<span>The polygon has 15 sides.</span>

4 0

3 years ago

The diameter of steel rods manufactured on two different extrusion machines is being investigated. Two random samples of sizes

devlian [24]

Answer:

(a) There is no evidence to support the claim that the two machines produce rods with different mean diameters.

P-value is 0.818

(b) 95% confidence interval for the difference in mean rod diameter is (-0.17, 0.27).

This interval shows that the difference in mean is between -0.17 and 0.27.

Step-by-step explanation:

(a) Null hypothesis: The two machines produce rods with the same mean diameter.

Alternate hypothesis: The two machines produce rods with different mean diameter.

Machine 1

mean = 8.73

variance = 0.35

n1 = 15

Machine 2

mean = 8.68

variance = 0.4

n2 = 17

pooled variance = [(15-1)0.35 + (17-1)0.4] ÷ (15+17-2) = 11.3 ÷ 30 = 0.38

Test statistic (t) = (8.73 - 8.68) ÷ sqrt[0.38(1/15 + 1/17)] = 0.05 ÷ 0.218 = 0.23

degree of freedom = n1+n2-2 = 15+17-2 = 30

Significance level = 0.05 = 5%

Critical values corresponding to 30 degrees of freedom and 5% significance level are -2.042 and 2.042.

Conclusion:

Fail to reject the null hypothesis because the test statistic 0.23 falls within the region bounded by the critical values -2.042 and 2.042.

There is no evidence to support the claim that the two machines produce rods with different mean diameters.

Cumulative area of test statistic is 0.5910

The test is a two-tailed test.

P-value = 2(1 - 0.5910) = 2×0.409 = 0.818

(b) Difference in mean = 8.73 - 8.68 = 0.05

pooled sd = sqrt(pooled variance) = sqrt(0.38) = 0.62

Critical value (t) = 2.042

E = t×pooled sd/√n1+n2 = 2.042×0.62/√15+17 = 0.22

Lower limit of difference in mean = 0.05 - 0.22 = -0.17

Upper limit of difference in mean = 0.05 + 0.22 = 0.27

95% confidence interval for the difference in mean rod diameter is between a lower limit of -0.17 and an upper limit of 0.27.

3 0

4 years ago

3/48 is what part of 1/12

snow_tiger [21]

Hi there!

3/48 is what part if 1/12? This question is pretty simple, and below is why:

If you split 3/48 into fourths, three of those fourths would be worth 1/12.

Hope this helps!

3 0

3 years ago

A friend offers to play a game, in which you roll 3 standard 6-sided dice. If all the dice roll

VMariaS [17]

Answer: The expected value is $0.32

Step-by-step explanation:

The expected value can be calculated as:

EV = ∑xₙ*pₙ

Where:

xₙ is the n-th event.

pₙ is the probability of the n-th event.

First, let's see the events in this situation and the probability of each event.

Lossing $1.

This happens when you roll all different numbers.

To calculate the number of combinations where you roll all different values, we first need to count the number of possible options for each roll, this is:

First dice: you have 6 options

Second dice: You have 5 options, because we remove the option that was rolled in the first dice.

Third dice: You have 4 options, because we removed the two outcomes showed in the two previous rolls.

Then the number of combinations is:

c = 6*5*4 = 120.

And the total number of combinations for rolling 3 dice is equal to the product between the number of outcomes for each dice, each dice has 6 possible outcomes, then the total number of outcomes is:

C = 6*6*6 = 216

The probability of rolling all different numbers will be equal to the quotient between the number of combinations where you roll all different values and the total number of combinations:

P₁ = 120/216 = 0.56

In the other case, where you roll at least two equal outcomes, you win $2.

The probability for this case will be the complement of the previous one, then the probability can be calculated as:

P₂ = 1 - P₁ = 1 - 0.56 = 0.44

Then the expected value will be:

EV = -$1*0.56 + $2*0.44 = $0.32

The expected value is $0.32

5 0

3 years ago

During one season a total of 453193 people attended a baseball teams games what is the value of the digit 5 in the number of peo

Mkey [24]

The value of the 5 is 50,000

6 0

3 years ago