Find a number which decreased by 18 is 5 times its opposite

Test scores are normally distributed with a mean of 500. Convert the given score to a z-score, using the given standard deviatio

Bond [772]

Answer:

The percentage of students who scored below 620 is 93.32%.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 500, \sigma = 80$

Percentage of students who scored below 620:

This is the pvalue of Z when X = 620. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{620 - 500}{80}$

$Z = 1.5$

$Z = 1.5$ has a pvalue of 0.9332

The percentage of students who scored below 620 is 93.32%.

3 0

3 years ago

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Or btao koi h meri baat samjhne wala h koi .. koi nhi h .. bc

8_murik_8 [283]

Answer:

Main hu haha

Step-by-step explanation:

hii!! how are you??

7 0

3 years ago

HELP PLEASE MATH!! A company is testing tires for wear and tear. A given tire is said to either pass the test (P) or fail the te

Xelga [282]

Answer:

PPF, PFF

Step-by-step explanation:

There are several ways you can list all the possible combinations. A couple of my favorite are a) use a binary counting sequence; b) use a gray code counting sequence.

Using the first method, the binary numbers 000 to 111 can be listed in numerical order as 000, 001, 010, 011, 100, 101, 110, 111. Letting 0=P and 1=F, the ones missing from your list are the ones in italics in my list.

Using the second method, we change the right-most character, then the middle one, and finally the left-most character so there is one change at a time: 000, 001, 011, 010, 110, 111, 101, 100.

After you have a list of all possible combinations, it is a simple matter to compare the given list to the list of possibilities to see which are missing.

5 0

3 years ago

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If x + y = 10 and x - y = 4, find the value of x² - y²

morpeh [17]

Answer:

x²-y² = 40

Step-by-step explanation:

Factorising x²-y²:

x²-y² = (x+y)(x-y)

This is due to the property that states:

a²+b² = (a+b)(a-b)

Substituting the given values into the above equation:

x²-y² = (10)(4)

= 40

Hence, x²-y² = 40

Hope this helps and be sure to have a wonderful time ahead at Brainly! :D

8 0

2 years ago

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The perimeter of a rectangular garden is 44 meters. The length of the rectangle is 5 less than twice the width. Find the length

defon

9514 1404 393

Answer:

width: 9 m
length: 13 m

Step-by-step explanation:

Let w represent the width. Then the length is 2w-5, and the perimeter is ...

P = 2(L+W)

44 = 2((2w-5) +w)

44 = 6w -10

54 = 6w

9 = w

2(9) -5 = 13 = length

The length of the rectangle is 13 meters; the width is 9 meters.

6 0

2 years ago