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ExtremeBDS [4]
3 years ago
9

A multiple choice test has four possible answers for each question. Let X be the number of correct responses in a test of 100 qu

estions if the student simply guesses on each question. The standard deviation of X is
a. 4.33.
b. 18.75.
c. 0.433.
Mathematics
1 answer:
dimulka [17.4K]3 years ago
7 0

Answer:

a. 4.33.

Step-by-step explanation:

If there is only one correct answer out of four alternatives, the expected proportion of correct answers is p =0.25

Sample size (n) = 100 questions

The standard deviation of a proportion 'p' is given by:

s=\sqrt{\frac{p*(1-p)}{n} }

Applying the given data:

s=\sqrt{\frac{0.25*(1-0.25)}{100}}\\s=0.0433

If X is the number of correct responses in 100 guesses, the standard deviation of X is:

\sigma = n*s=100*0.0433\\\sigma = 4.33

The standard deviation of X is 4.33 questions.

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Answer:

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A number, X, rounded to 1 decimal place is 3,7<br> Write down the error interval for x,
sp2606 [1]

Answer:

The error interval for x is:

                 [3.65,3.74]

Step-by-step explanation:

The number after rounding off is obtained as:

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We know that any of the number below on rounding off the number to the first decimal place will result in 3.7:

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( Because if we have to round off a number present in decimals to n place then if  there is a  number greater than or equal to 5 at n+1 place then it will result to the one higher digit  at nth place on rounding off and won't change the digit if it less than 5 )

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            [3.65,3.74]

6 0
2 years ago
Enter the number 46.1979 rounded to the nearest hundredth (two decimal places)
muminat

Answer:

It should be 46.20

Step-by-step explanation:

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