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3 years ago

– Jack can paint a room in 9 hours alone. If Sara helps, they can do the job in 5 hours. How long

Mathematics

1 answer:

Dafna11 [192]3 years ago

8 0

Answer: 9

Step-by-step explanation:

If Jack can paint the room in 9 hours by his self she can only do the same

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PRACTICE ANOTHER The administration of a large university wants to take a random sample to measure student opinion of a new food

Reil [10]

Answer:

81 samples

Step-by-step explanation:

According to the empirical rule :

Possible values of the sample mean is within 3 standard deviations of the population mean :

μ ± 3 sd(x) ; sd(x) = standard deviation of sampling distribution.

3 * sd(x) = 1

sd(x) = 1/3

Recall:

Standard deviation of sampling distribution, sd(x)

sd(x) = σ / sqrt(n)

1/3 = 3 / sqrt(n)

Square both sides

1/9 = 9/n

Cross multiply :

n * 1 = 9 * 9

n = 81

3 0

2 years ago

Solve each inequality using the Addition Property of Inequality.

Law Incorporation [45]

Answer:

y ≥ 28

Step-by-step explanation:

Isolate the variable. Treat the inequality sign as a equal sign, what you do to one side, you do to the other. Add 6 to both sides:

y - 6 (+6) ≥ 22 (+6)

y ≥ 22 + 6

y ≥ 28

y ≥ 28 is your answer.

4 0

3 years ago

From the square with the rib is the cylinder wrapper built. Express the volume of this cylinder as a function of the rib a

Alisiya [41]

Answer:

Look I’m not an expert in math but here it is: 7.4

Step-by-step explanation:

Or in fraction form 37/500

7 0

3 years ago

(i) 809, 708, 607, _____, _ class 4<br>__class 4

schepotkina [342]

Answer:

809, 708, 607, 506, 405, 304, 203, 102, 1, -100

Step-by-step explanation:

809, 708, 607, _____, _______

First term = 809

Second term = 708

Third term = 607

Difference between first term and second term = 809 - 708

= 101

Difference between second term and third term = 708 - 607

= 101

Therefore, the common difference is 101

Fourth term = 607 - 101

= 506

Fifth term = 506 - 101

= 405

Sixth term = 405 - 101

= 304

Seventh term = 304 - 101

= 203

Eighth term = 203 - 101

= 102

Ninth term = 102 - 101

= 1

Tenth term = 1 - 101

= - 100

809, 708, 607, 506, 405, 304, 203, 102, 1, -100

4 0

2 years ago

Let ABC be an isosceles triangle with AB = AC and ∠BAC=30°. Side AB and the median AD contain points Q and P respectively (point

Svet_ta [14]

Answer:

15°

Step-by-step explanation:

Since P is on the median of ΔABC, it is equidistant from points B and C as well as from C and Q. Thus, points B, C, and Q all lie on a circle centered at P. (See the attached diagram.)

The base angles (B and C) of triangle ABC are (180° -30°)/2 = 75°. This means arc QC of the circle centered at P has measure 150°. The diameter of circle P that includes point Q is defined to intersect circle P at R.

Central angle RPC is the difference between arcs QR and QC, so is 180° -150° = 30°. Inscribed angle RQC has half that measure, so is 15°. Angle PQC has the same measure as angle RQC, so is 15°.

Angle PQC is 15°.

5 0

3 years ago