Solve the equation. 4x = -28 x=____

dybincka [34]

8×1+5×(1/10)+9×(1/1000)
8+5×(.1)+9×(.001)
8+.5+.009
Answer is 8.509

7 0

3 years ago

Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used. Match each situation to its corresponding

dlinn [17]

Answer:

I mean how can I answer this???????????????????????

5 0

3 years ago

Kaylah's cell phone has a mass of 58,000 centigrams What is the mass of her phone in grams? The mass of Kaylah's cell phone is ?

ASHA 777 [7]

The answer is 580 grams.

8 0

3 years ago

The circumference of a circle is equal to n times its diameter. Estimate the circumference of a round swimming pool that has a d

sdas [7]

Answer: An estimate done quickly: The circumference is about 75 ft.

Step-by-step explanation:

Round π to 3, and 24 to 25. 3 times 25 is 75

A more exact value would be 75.36

3.14 × 24 = 75.36

5 0

2 years ago

A manufacturer produces light bulbs that have a mean life of at least 500 hours when the production process is working properly.

denpristay [2]

Answer:

We conclude that the population mean light bulb life is at least 500 hours at the significance level of 0.01.

Step-by-step explanation:

We are given that a manufacturer produces light bulbs that have a mean life of at least 500 hours when the production process is working properly. The population standard deviation is 50 hours and the light bulb life is normally distributed.

You select a sample of 100 light bulbs and find mean bulb life is 490 hours.

Let $\mu$ = population mean light bulb life.

So, Null Hypothesis, $H_0$ : $\mu \geq$ 500 hours {means that the population mean light bulb life is at least 500 hours}

Alternate Hypothesis, $H_A$ : $\mu$ < 500 hours {means that the population mean light bulb life is below 500 hours}

The test statistics that would be used here One-sample z test statistics as we know about the population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean bulb life = 490 hours

σ = population standard deviation = 50 hours

n = sample of light bulbs = 100

So, the test statistics = $\frac{490-500}{\frac{50}{\sqrt{100} } }$

= -2

The value of z test statistics is -2.

Now, at 0.01 significance level the z table gives critical value of -2.33 for left-tailed test.

Since our test statistic is higher than the critical value of z as -2 > -2.33, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which we fail to reject our null hypothesis.

Therefore, we conclude that the population mean light bulb life is at least 500 hours.

7 0

3 years ago

Solve the equation. 4x = -28 x=_____