1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tju [1.3M]
3 years ago
14

Wendy has taken two tests with scores of 77 and 80. To get an 82

Mathematics
1 answer:
tiny-mole [99]3 years ago
3 0

Answer:

89

Step-by-step explanation:

Given that Wendy took 2 tests and scored, 77 and 80 respectively, let x represent the grade of Wendy's third test.

To get an average grade of 82, let's generate an equation to find x (Wendy's grade on her third test).

Average grade = sum of all 3 grades all over 3

82 = \frac{77 + 80 + x}{3}

82 = \frac{157 + x}{3}

Multiply 3 by both sides

82*3 = \frac{157 + x}{3}*3

246 = 157 + x

Subtract 157 from each side of the equation

246 - 157 = 157 + x - 157

89 = x

Wendy must score 89 on her third test to have an average of 82.

You might be interested in
he value of a piece of machinery, in dollars, after t years is described by the function below. f(t)=12,500−1,600t What is the v
Maru [420]

Answer: d 10900

Step-by-step explanation:

4 0
2 years ago
Read 2 more answers
The diameter of steel rods manufactured on two different extrusion machines is being investigated. Two random samples of sizes
devlian [24]

Answer:

(a) There is no evidence to support the claim that the two machines produce rods with different mean diameters.

P-value is 0.818

(b) 95% confidence interval for the difference in mean rod diameter is (-0.17, 0.27).

This interval shows that the difference in mean is between -0.17 and 0.27.

Step-by-step explanation:

(a) Null hypothesis: The two machines produce rods with the same mean diameter.

Alternate hypothesis: The two machines produce rods with different mean diameter.

Machine 1

mean = 8.73

variance = 0.35

n1 = 15

Machine 2

mean = 8.68

variance = 0.4

n2 = 17

pooled variance = [(15-1)0.35 + (17-1)0.4] ÷ (15+17-2) = 11.3 ÷ 30 = 0.38

Test statistic (t) = (8.73 - 8.68) ÷ sqrt[0.38(1/15 + 1/17)] = 0.05 ÷ 0.218 = 0.23

degree of freedom = n1+n2-2 = 15+17-2 = 30

Significance level = 0.05 = 5%

Critical values corresponding to 30 degrees of freedom and 5% significance level are -2.042 and 2.042.

Conclusion:

Fail to reject the null hypothesis because the test statistic 0.23 falls within the region bounded by the critical values -2.042 and 2.042.

There is no evidence to support the claim that the two machines produce rods with different mean diameters.

Cumulative area of test statistic is 0.5910

The test is a two-tailed test.

P-value = 2(1 - 0.5910) = 2×0.409 = 0.818

(b) Difference in mean = 8.73 - 8.68 = 0.05

pooled sd = sqrt(pooled variance) = sqrt(0.38) = 0.62

Critical value (t) = 2.042

E = t×pooled sd/√n1+n2 = 2.042×0.62/√15+17 = 0.22

Lower limit of difference in mean = 0.05 - 0.22 = -0.17

Upper limit of difference in mean = 0.05 + 0.22 = 0.27

95% confidence interval for the difference in mean rod diameter is between a lower limit of -0.17 and an upper limit of 0.27.

3 0
3 years ago
A group of workers can plant 49 acres in 7 days. What is there rate in acres per day?
Galina-37 [17]

Answer:

Step-by-step explanation:

343

8 0
2 years ago
Read 2 more answers
A positive integer is twice another.the sum of the reciprocal of the two positive integer is 3/14. Find the integers
icang [17]

Answer:

\huge\boxed{14\ \text{and}\ 7}

Step-by-step explanation:

n,\ m-\text{positive integer}\\\\n=2m-\text{a positive integer is twice another}\\\\\dfrac{1}{n}+\dfrac{1}{m}=\dfrac{3}{14}-\text{the sum of the reciprocal of the two positive integer is }\ \dfrac{3}{14}\\\\\text{We have the system of equations:}\\\\\left\{\begin{array}{ccc}n=2m&(1)\\\dfrac{1}{n}+\dfrac{1}{m}=\dfrac{3}{14}&(2)\end{array}\right

\text{Substitute (1) to (2):}\\\\\dfrac{1}{2m}+\dfrac{1}{m}=\dfrac{3}{14}\\\\\dfrac{1}{2m}+\dfrac{1\cdot2}{m\cdot2}=\dfrac{3}{14}\\\\\dfrac{1}{2m}+\dfrac{2}{2m}=\dfrac{3}{14}\\\\\dfrac{1+2}{2m}=\dfrac{3}{14}\\\\\dfrac{3}{2m}=\dfrac{3}{14}\Rightarrow2m=14\qquad\text{divide both sides by 2}\\\\\dfrac{2m}{2}=\dfrac{14}{2}\\\\\boxed{m=7}

\text{Substitute it to (1):}\\\\n=2\cdot7\\\\\boxed{n=14}

8 0
2 years ago
The hiski s family spends $600 per month on groceries for the family. If this is 15% of their monthly budget , then what is thei
ad-work [718]

I think that it is $4,000

8 0
3 years ago
Other questions:
  • Sal is building a robot, if he puts a sphere on top of a cylinder. What would happen?
    12·2 answers
  • A certain liquid has a density of 2.67 g/cm3. 30.5 mL of this liquid would have a mass of ________ Kg.
    6·1 answer
  • what is the inverse statement of the following conditional statment : if you understand the review, then you will pass the test
    15·1 answer
  • Choose the scenario that can be represented by 4/7
    5·2 answers
  • 37<br> a<br> 12<br> В<br> 35<br> C<br> Find tan(a) in the triangle.
    14·1 answer
  • Is −5+(2.5+3 1/5)⋅4.25 equivalent to −5+(5.7)⋅4.25 yes or no?
    7·1 answer
  • 5. A television set is sale at P13,499 in cash or on installment terms, P2,500 each
    8·1 answer
  • Suppose that there are two types of tickets to a show: advance and same-day. Advance tickets cost 25$ and same-day tickets cost
    7·1 answer
  • The angle of elevation of the top of a tower from two points 121 m and 144 m away from the foot of the tower on th same side are
    15·1 answer
  • 11/5 =<br> Help me please
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!