Plzzzzz teach this..... I wiil Mark as brainlist answer if correct

-7a-3<2a Please solve

rusak2 [61]

Answer:

a>-1/3

Step-by-step explanation:

-7a-2a<3

-9a<3

-a<3/9

a>-3/9

a>-1/3

You switch the sign because your dividing by a negative.

4 0

3 years ago

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A country is considering raising the speed limit on a road because they claim that the mean speed of vehicles is greater than 30

kondaur [170]

Answer:

We conclude that speed is greater than 30 miles per hour.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 30 miles per hour

Sample mean, $\bar{x}$ = 35 miles per hour

Sample size, n = 15

Alpha, α = 0.01

Sample standard deviation, s = 4.7 miles per hour

First, we design the null and the alternate hypothesis

$H_{0}: \mu = 30\text{ miles per hour}\\H_A: \mu > 30\text{ miles per hour}$

We use one-tailed(right) t test to perform this hypothesis.

Formula:

$t_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{s}{\sqrt{n}} }$

Putting all the values, we have

$t_{stat} = \displaystyle\frac{35 - 30}{\frac{4.7}{\sqrt{15}} } = 4.120$

Now, $t_{critical} \text{ at 0.01 level of significance, 14 degree of freedom } = 2.624$

Since,

$t_{stat} > t_{critical}$

We fail to accept the null hypothesis and reject it. We accept the alternate hypothesis and conclude that speed is greater than 30 miles per hour.

We calculate the p-value.

P-value = 0.00052

Since p value is lower than the significance level, we reject the null hypothesis and accept the alternate hypothesis. We conclude that speed is greater than 30 miles per hour.

6 0

3 years ago

Use the distributive property 3(4×+5)=「21×+0

Dmitry_Shevchenko [17]

Answer:3(5+7)3(5+7)

Step-by-step explanation:

3 0

1 year ago

Which equation can be used to find the measure of an angle that is supplementary to POS

Reil [10]

Two angles are called supplementary if their sum is equal to 180°
to find the measure of an angle that is supplementary to POS, we have the following equation

measPOS + x = 180°, where x is supplementary to POS

3 0

3 years ago

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Question Help Suppose that the lifetimes of light bulbs are approximately normally distributed, with a mean of 5656 hours and a

koban [17]

Answer:

a)3.438% of the light bulbs will last more than 6262 hours.

b)11.31% of the light bulbs will last 5252 hours or less.

c) 23.655% of the light bulbs are going to last between 5858 and 6262 hours.

d) 0.12% of the light bulbs will last 4646 hours or less.

Step-by-step explanation:

Normally distributed problems can be solved by the z-score formula:

On a normaly distributed set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a value X is given by:

$Z = \frac{X - \mu}{\sigma}$

After we find the value of Z, we look into the z-score table and find the equivalent p-value of this score. This is the probability that a score will be LOWER than the value of X.

In this problem, we have that:

The lifetimes of light bulbs are approximately normally distributed, with a mean of 5656 hours and a standard deviation of 333.3 hours.

So $\mu = 5656, \sigma = 333.3$

(a) What proportion of light bulbs will last more than 6262 hours?

The pvalue of the z-score of $X = 6262$ is the proportion of light bulbs that will last less than 6262. Subtracting 100% by this value, we find the proportion of light bulbs that will last more than 6262 hours.