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Karo-lina-s [1.5K]

2 years ago

15

A surgery shows that 85 percent of students carry a backpack to school. Is there are 230 students in the school,how many student

s carry a backpack

1 answer:

GenaCL600 [577]2 years ago

4 0

The answer is 78% because of the heat

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Can someone tell me the answer to this plz

Tpy6a [65]

M8 =43.
Reason:
134+ M8 =180(degrees). This is because angles on a straight line =180 (degrees)

180-134=M8
Therefore:
M<8 =180-134= 43 (degrees)

Hope this helps and makes sense.

Please mark as a brainliest (crowns)

4 0

2 years ago

Help asap will give 40 points

Vera_Pavlovna [14]

Answer: 1/3

Step-by-step explanation:

3 0

2 years ago

a certain number of two digit is three times the sum of its digit and if 45 added to it the digit will be reversed find the numb

bogdanovich [222]

· Author has 184 answers and 67.6K answer views
Let the number be (10 x + y)

Then, 10 x + y = 3 * (x + y) (given)

Or, 10 x + y = 3 x + 3 y

Or, 10 x - 3 x = 3 y - y

Or, 7x = 2 y

Or, x = 2 y / 7 ( Eq. 1)

Also, 10 x + y + 45 = 10 y + x ( given)

Or, 10 x - x = 10 y - y - 45

Or, 9 x = 9 y - 45 ( Eq. 2)

Substituting the value of x from (Eq. 1) in (Eq. 2), we have:

9 * 2 y / 7 = 9 y - 45

Or, (9 y ) - (18 y / 7) = 45

Or, 63 y - 18 y = 315

Or, 45 y = 315

Or, y = 7

From (Eq. 1),

x = 2 * 7 / 7 = 2

So, the number is 10 x + y = (10 * 2) + 7 = (20 + 7) = 27

Answer

Check:

Sum of the digits = 2 + 7 = 9

9 * 3 = 27 ✓

Adding 45 to the number 27, we get 72. So, the digits get reversed.

5 0

2 years ago

9. If f(x)=x². g(x)=2x-1. and h(x) =find the following.

postnew [5]

Answer:

Please see the attached picture ! :D

-------- HappY LearninG <3 ----------

8 0

2 years ago

A professor wishes to discover if seniors skip more classes than freshmen. Suppose he knows that freshmen skip 2% of their class

KIM [24]

Answer:

We conclude that seniors skip more than 2% of their classes at 0.01 level of significance.

Step-by-step explanation:

We are given that a professor wishes to discover if seniors skip more classes than freshmen. Suppose he knows that freshmen skip 2% of their classes.

He randomly samples a group of seniors and out of 2521 classes, the group skipped 77.

<u><em /></u>

<u><em>Let p = percentage of seniors who skip their classes.</em></u>

So, Null Hypothesis, $H_0$ : p $\leq$ 2% {means that seniors skip less than or equal to 2% of their classes}

Alternate Hypothesis, $H_A$ : p > 2% {means that seniors skip more than 2% of their classes}

The test statistics that will be used here is <u>One-sample z proportion</u> <u>statistics</u>;

T.S. = $\frac{\hat p-p}{{\sqrt{\frac{\hat p(1-\hat p)}{n} } } } }$ ~ N(0,1)

where, $\hat p$ = sample proportion of seniors who skipped their classes = $\frac{77}{2521}$

n = sample of classes = 2521

So, <u><em>test statistics</em></u> = $\frac{\frac{77}{2521} -0.02}{{\sqrt{\frac{\frac{77}{2521}(1-\frac{77}{2521})}{2521} } } } }$

= 3.08

The value of the test statistics is 3.08.

Now at 0.01 significance level, <u>the z table gives critical value of 2.3263 for right-tailed test</u>. Since our test statistics is more than the critical value of z as 2.3263 < 3.08, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which <u>we reject our null hypothesis</u>.

Therefore, we conclude that seniors skip more than 2% of their classes.

6 0

3 years ago