How many students studied for exactly 2 hours? A. 0 B. 2 C. 4 D. Not enough information

Pls help quick will put brainliest

Olin [163]

Answer:

m<SQP=124°

Step-by-step explanation:

Hi there!

We're given ΔQRS, the measure of <R (90°), and the measure of <S (34°)

we need to find m<SQP (given as x+72°)

exterior angle theorem is a theorem that states that an exterior angle (an angle on the OUTSIDE of a shape) is equal to the sum of the two remote interior angles (the angle OUTSIDE of a shape will be equal to the sum of 2 angles that are OPPOSITE to that angle).

that means that m<SQP=m<R+m<S (Exterior angle theorem)

substitute the known values into the equation

x+72°=90°+34° (substitution)

combine like terms on both sides

x+72°=124° (algebra)

subtract 72 from both sides

x=52° (algebra)

however, that's just the value of x. Because m<SQP is x+72°, add 52 and 72 together to get the value of m<SQP

m<SQP=x+72°=52°+72°=124° (substitution, algebra)

Hope this helps!

4 0

3 years ago

The College Board SAT college entrance exam consists of three parts: math, writing and critical reading (The World Almanac 2012)

Wittaler [7]

Answer:

Yes, there is a difference between the population mean for the math scores and the population mean for the writing scores.

Test Statistics = $\frac{Dbar - \mu_D}{\frac{s_D}{\sqrt{n} } }$ follows $t_n_- _1$ .

Step-by-step explanation:

We are provided with the sample data showing the math and writing scores for a sample of twelve students who took the SAT ;

Let A = Math Scores ,B = Writing Scores and D = difference between both

So, $\mu_A$ = Population mean for the math scores

$\mu_B$ = Population mean for the writing scores

Let $\mu_D$ = Difference between the population mean for the math scores and the population mean for the writing scores.

Null Hypothesis, $H_0$ : $\mu_A = \mu_B$ or $\mu_D$ = 0

Alternate Hypothesis, $H_1$ : $\mu_A \neq \mu_B$ or $\mu_D \neq$ 0

Hence, Test Statistics used here will be;

$\frac{Dbar - \mu_D}{\frac{s_D}{\sqrt{n} } }$ follows $t_n_- _1$ where, Dbar = Bbar - Abar

$s_D$ = $\sqrt{\frac{\sum D_i^{2}-n*(Dbar)^{2}}{n-1}}$

n = 12

Student Math scores (A) Writing scores (B) D = B - A

1 540 474 -66

2 432 380 -52

3 528 463 -65

4 574 612 38

5 448 420 -28

6 502 526 24

7 480 430 -50

8 499 459 -40

9 610 615 5

10 572 541 -31

11 390 335 -55

12 593 613 20

Now Dbar = Bbar - Abar = 489 - 514 = -25

Bbar = $\frac{\sum B_i}{n}$ = $\frac{474+380+463+612+420+526+430+459+615+541+335+613}{12}$ = 489

Abar = $\frac{\sum A_i}{n}$ = $\frac{540+432+528+574+448+502+480+499+610+572+390+593}{12}$ = 514

∑ $D_i^{2}$ = 22600 and $s_D$ = $\sqrt{\frac{\sum D_i^{2}-n*(Dbar)^{2}}{n-1}}$ = $\sqrt{\frac{22600 - 12*(-25)^{2} }{12-1} }$ = 37.05

So, Test statistics = $\frac{Dbar - \mu_D}{\frac{s_D}{\sqrt{n} } }$ follows $t_n_- _1$

= $\frac{-25 - 0}{\frac{37.05}{\sqrt{12} } }$ follows $t_1_1$ = -2.34

Now at 5% level of significance our t table is giving critical values of -2.201 and 2.201 for two tail test. Since our test statistics doesn't fall between these two values as it is less than -2.201 so we have sufficient evidence to reject null hypothesis as our test statistics fall in the rejection region .

Therefore, we conclude that there is a difference between the population mean for the math scores and the population mean for the writing scores.

8 0

2 years ago

Mrs. Blalock gave her students a math test. Each problem on the test was worth 4.5 points. The grade on the test, y, can be calc

umka2103 [35]

Answer:

4,5*16=y

y=72

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

memo is one year older than twice tecatito's age if the sum of their ages is 52 years, how old are both of them

ch4aika [34]

Answer: Memo would be 35 and Tecatito would be 17

Explanation:

17 + (17x2 +1) =52

17 + 35 = 52

Hope this helps!

4 0

3 years ago

If a worker can do his job in 5 hours, and a student can do the same job in 8 hours, what part of the work is left to finish aft

Aleks [24]

Answer:

Part of work left to finish after two work hours is 7/20

Step-by-step explanation:

Firstly, we need to calculate their joint work rate

That will be;

1/(1/5 + 1/8) = 1/(13/40) = 40/13

This means that they will complete the task in 40/13 hours

1 whole part takes 40/13

x part will take 2 hours

x * 40/13 = 2

40x = 26

x = 26/40

So the part that will be completed in two hours is 26/40

This means that the part left to complete will be:

1 - 26/40 = 14/40 = 7/20

8 0

2 years ago

Read 2 more answers