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jeka57 [31]
3 years ago
5

Recently, Frank took a one-hundred question aptitude test where each correct answer scored 5 points, each incorrect answer score

d -2 points, and each question not answered scored zero points. Frank answered 80 questions and scored 232 points. How many questions did he answer correctly?
Mathematics
2 answers:
Neporo4naja [7]3 years ago
8 0

Answer:

56 questions were correctly answered by Frank.

Step-by-step explanation:

Let Frank answered the number of correct questions = x

Let wrong answers given by Frank = y

By statement 1 "Frank answered 80 questions".

Equation will be x + y = 80 ---------(1)

Statement 2 "Frank scored 232 points."

equation will be 5x - 2y = 232 ------(2)

We have to calculate number of correct answers.

Multiply equation (1) by (2) then add it to equation (1).

(2x + 2y) + (5x - 2y) = 160 + 232

7x = 392

x = 56

Therefore, 56 questions were correctly answered by Frank.

Lyrx [107]3 years ago
3 0
Im guessing he answered 30 correct, let me know if im correct
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Ann needs 42 feet of fabric to make a small quilt. How many yards of fabric should she buy. a. 13yards, b. 14yards, c. 21yards,
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B. she should buy 14 yards of fabric,because 14×3=42 so there is your 42 feet.
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4 years ago
Two machines are used for filling glass bottles with a soft-drink beverage. The filling process have known standard deviations s
stellarik [79]

Answer:

a. We reject the null hypothesis at the significance level of 0.05

b. The p-value is zero for practical applications

c. (-0.0225, -0.0375)

Step-by-step explanation:

Let the bottles from machine 1 be the first population and the bottles from machine 2 be the second population.  

Then we have n_{1} = 25, \bar{x}_{1} = 2.04, \sigma_{1} = 0.010 and n_{2} = 20, \bar{x}_{2} = 2.07, \sigma_{2} = 0.015. The pooled estimate is given by  

\sigma_{p}^{2} = \frac{(n_{1}-1)\sigma_{1}^{2}+(n_{2}-1)\sigma_{2}^{2}}{n_{1}+n_{2}-2} = \frac{(25-1)(0.010)^{2}+(20-1)(0.015)^{2}}{25+20-2} = 0.0001552

a. We want to test H_{0}: \mu_{1}-\mu_{2} = 0 vs H_{1}: \mu_{1}-\mu_{2} \neq 0 (two-tailed alternative).  

The test statistic is T = \frac{\bar{x}_{1} - \bar{x}_{2}-0}{S_{p}\sqrt{1/n_{1}+1/n_{2}}} and the observed value is t_{0} = \frac{2.04 - 2.07}{(0.01246)(0.3)} = -8.0257. T has a Student's t distribution with 20 + 25 - 2 = 43 df.

The rejection region is given by RR = {t | t < -2.0167 or t > 2.0167} where -2.0167 and 2.0167 are the 2.5th and 97.5th quantiles of the Student's t distribution with 43 df respectively. Because the observed value t_{0} falls inside RR, we reject the null hypothesis at the significance level of 0.05

b. The p-value for this test is given by 2P(T0 (4.359564e-10) because we have a two-tailed alternative. Here T has a t distribution with 43 df.

c. The 95% confidence interval for the true mean difference is given by (if the samples are independent)

(\bar{x}_{1}-\bar{x}_{2})\pm t_{0.05/2}s_{p}\sqrt{\frac{1}{25}+\frac{1}{20}}, i.e.,

-0.03\pm t_{0.025}0.012459\sqrt{\frac{1}{25}+\frac{1}{20}}

where t_{0.025} is the 2.5th quantile of the t distribution with (25+20-2) = 43 degrees of freedom. So

-0.03\pm(2.0167)(0.012459)(0.3), i.e.,

(-0.0225, -0.0375)

8 0
3 years ago
Which property does this represent -3x1=-3
katrin2010 [14]

The property used is: Multiplicative identity

Step-by-step explanation:

We need to identify the property in the equation : -3\times 1=-3

The property used is: Multiplicative identity

Multiplicative identity

The multiplicative identity property is defined as if you multiply a number by 1, the result of multiplication is that original number.

In the given expression -3\times 1=-3 -3 is multiplied by 1 to get -3 so, multiplicative identity.

Keywords: Properties of Multiplication

Learn more about  Properties of Multiplication at:

  • brainly.com/question/2369634
  • brainly.com/question/5639299
  • brainly.com/question/5527192

#learnwithBrainly

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Oksi-84 [34.3K]

Answer:

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Step-by-step explanation:

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slega [8]

Answer:

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Step-by-step explanation:

** Ik this might sound stupid but it helps

Draw the point on a graph. Then imagine the the line x=3 as the straight edge of protractor and do a full 180° on the line. it should land in the 4th quadrant and on the same line of x=3

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