Lauren jogs at a rate of 2 miles every 2/5 hour what is her unit rate ?

Pls help i will mark brainliest

aksik [14]

Answer:

the answer is the first one I think but I'm pretty sure

6 0

3 years ago

What is the word phrase for this algebraic expression z/8-9

ivann1987 [24]

The phrase would be: "z divided by the difference of 8 and 9"

5 0

3 years ago

Can someone help me for this

garri49 [273]

Answer:

the straight line will always equal 180 degrees.

180-125-35=20

the answer for the missing degree is 20

7 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

Solving Exponential and Logarithmic Equations In Exercise, solve for x. In 2x - In(3x - 1) = 0

LenKa [72]

Answer:

$\frac{-1}{3x^2-x}$