8 1/2 or 8.5 x11 = 93.5 square inches thus,
1000 square inches divided by 93.5 square inches
1000/93.5 ~10.695
that mean that Jodi can cut out about 10 pieces of paper measuring 8 1/2 x 11 inches.

4 0

3 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

X² + 4x + 3 = 0 Can someone please help me solve this quadratic equation

gavmur [86]

Answer:

Step-by-step explanation:

x= -1 and -3

What when multiplied is +3 but when added is 4? 3 and 1. You then get (x+3)(x+1) is the first part of the answer. If you want to find x, set x+3 to 0. x+3=0. Then subtract 3 from both sides to get x by itself. x= -3. Do the same with the x+1.

8 0

3 years ago

The ratio of the number of hamsters to the number of mice in a pet store is 3 to 2. How many hamsters are there, if there are 12

aleksandrvk [35]

Answer:

Step-by-step explanation:

you can do 12/2 to get 6 (the scale factor) and then multiply 3 by 6 and get 18

6 0

3 years ago