Ask question

Ask question

All categories

3 years ago

13

A pencil decreases in size by 1/12 millimeters per day. The total change in size of the pencil is -7/9 millimeters. How many day

s has the pencil been decreasing?

1 answer:

AlekseyPX3 years ago

3 0

9 1/3 days

Step-by-step explanation:

If the total change in the size of the pencil is -7/9 millimeters. Then the actual change itself is 7/9 which is a positive value.

If each day the pencil changes by 1/12 millimeters, how many 1/12 millimeters are there in 7/9 millimeters. This is a division query;

7/9 ÷ 1/12 = 7/9 * 12/1 = 28/3

= 9 & 1/3 days

Learn More:

For more on fractions check out;

brainly.com/question/1878884

brainly.com/question/78672

#LearnWithBrainly

You might be interested in

X <-4 graphed as an inequality on a number line

iris [78.8K]

See it is < and not ≤ so we don't include -4

put a circle around -4 but don't shade it in
to get there, move 4 units left from 0

then we see x is less than -4
so shade to the left of the circle

7 0

3 years ago

Use technology or a z-score table to answer the question.

Alik [6]

Answer:

The second choice: Approximately $65.2\%$ of the pretzel bags here will contain between 225 and 245 pretzels.

Step-by-step explanation:

This explanation uses a z-score table where each $z$ entry has two decimal places.

Let $\mu$ represent the mean of a normal distribution of variable $X$ . Let $\sigma$ be the standard deviation of the distribution. The z-score for the observation $x$ would be:

$\displaystyle z = \frac{x - \mu}{\sigma}$ .

In this question,

$\mu = 240$ .
$\sigma = 9.3$ .

Calculate the z-score for $x_1 = 225$ and $x_2 = 245$ . Keep in mind that each entry in the z-score table here has two decimal places. Hence, round the results below so that each contains at least two decimal places.

$\begin{aligned} z_1 &= \frac{x_1 - \mu}{\sigma} \\ &= \frac{225 - 240}{9.3} \approx -1.61\end{aligned}$ .

$\begin{aligned} z_2 &= \frac{x_2 - \mu}{\sigma} \\ &= \frac{245 - 240}{9.3} \approx 0.54\end{aligned}$ .

The question is asking for the probability $P(225 \le X \le 245)$ (where $X$ is between two values.) In this case, that's the same as $P(-1.61 \le Z \le 0.54)$ .

Keep in mind that the probabilities on many z-table correspond to probability of $P(Z \le z)$ (where $Z$ is no greater than one value.) Therefore, apply the identity $P(z_1 \le Z \le z_2) = P(Z \le z_2) - P(Z \le z_1)$ to rewrite $P(-1.61 \le Z \le 0.54)$ as the difference between two probabilities:

$P(-1.61 \le Z \le 0.54) = P(Z \le 0.54) - P(Z \le -1.61)$ .

Look up the z-table for $P(Z \le 0.54)$ and $P(Z \le -1.61)$ :

$P(Z \le 0.54)\approx 0.70540$ .
$P(Z \le -1.61) \approx 0.05370$ .

$\begin{aligned}& P(225 \le X \le 245) \\ &= P\left(\frac{225 - 240}{9.3} \le Z \le \frac{245 - 240}{9.3}\right)\\&\approx P(-1.61 \le Z \le 0.54) \\ &= P(Z \le 0.54) - P(Z \le -1.61)\\ &\approx 0.70540 - 0.05370 \\& \approx 0.65.2 \\ &= 65.2\% \end{aligned}$ .

3 0

3 years ago

What is NOT true about a direct proportion

SVEN [57.7K]

It’s graph must go through the origin ?

5 0

3 years ago

In ΔOPQ, the measure of ∠Q=90°, the measure of ∠O=26°, and QO = 4.9 feet. Find the length of PQ to the nearest tenth of a foot.

Step2247 [10]

Given:

In ΔOPQ, m∠Q=90°, m∠O=26°, and QO = 4.9 feet.

To find:

The measure of side PQ.

Solution:

In ΔOPQ,

$m\angle O+m\angle P+m\angle Q=180^\circ$ [Angle sum property]

$26^\circ+m\angle P+90^\circ=180^\circ$

$m\angle P+116^\circ=180^\circ$

$m\angle P=180^\circ -116^\circ$

$m\angle P=64^\circ$

According to Law of Sines, we get

$\dfrac{a}{\sin A}=\dfrac{b}{\sin B}=\dfrac{c}{\sin C}$

Using the Law of Sines, we get

$\dfrac{p}{\sin P}=\dfrac{o}{\sin O}$

$\dfrac{QO}{\sin P}=\dfrac{PQ}{\sin O}$

Substituting the given values, we get

$\dfrac{4.9}{\sin (64^\circ)}=\dfrac{PQ}{\sin (26^\circ)}$

$\dfrac{4.9}{0.89879}=\dfrac{PQ}{0.43837}$

$\dfrac{4.9}{0.89879}\times 0.43837=PQ$

$2.38989=PQ$

Approximate the value to the nearest tenth of a foot.

$PQ\approx 2.4$

Therefore, the length of PQ is 2.4 ft.

4 0

3 years ago

B(7, 2) and C(-1,-9) are the endpoints of a line segment. What is the midpoint M of that line

Oksana_A [137]

Answer:

(3,-3.5)

Step-by-step explanation:

$Mid-point formula : \frac{ x_{1} +x_{2}} {2}, \frac{y_{1}+y_{2} }{2} \\\\x=\frac{7+(-1)}{2} , y= \frac{2+(-9)}{2} \\x= \frac{6}{2} , y= \frac{-7}{2} \\x=3 , y= -3.5$

Midpoint M of the line segment is (3,-3.5)

4 0

4 years ago