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Inga [223]
3 years ago
13

John's Mathematics exam mark this year is increased by 5% to 84. Find his Mathematics exam mark

Mathematics
2 answers:
Svet_ta [14]3 years ago
8 0

Answer:

80%

Step-by-step explanation:

Let's call the past exam mark m,

m*105%=84

m*105/100=84

m=84/(105/100)

m=80

Hope this helps!

nadya68 [22]3 years ago
3 0

Answer:

80

Step-by-step explanation:

new value = 84

old value = n

can use percent change formula:  (new value - old value) / old value = 5/100

\frac{84-n}{n} = \frac{5}{100}

cross-multiply (you can simplify 5/100 to be 1/20 first):  20(84 - n) = n

1680 - 20n = n

1680 = 21n

n = 80

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Sophie [7]

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• As mentioned above, first step would be,

adding 5 to both sides

=> (4/7)x - 5 + 5 = -13 + 5

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• Now, transporting 7 from L.H.S. to R.H.S

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• Now in the same way, transporting 4 from L.H.S. to R.H.S

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• And in this way, or taking<u> (Add 5 to both sides)</u> as our first step, we find that the value of x is -14.

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7 0
3 years ago
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Step-by-step explanation:

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2 years ago
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For more see Law of Sines.

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c

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Answer:

There is not sufficient evidence to support the claim.

Step-by-step explanation:

The claim to be tested is:

The mean respiration rate (in breaths per minute) of students in a large statistics class is less than 32.

To test this claim the hypothesis can be defined as follows:

<em>H₀</em>: The mean respiration rate of students is 32, i.e. <em>μ</em> = 32.

<em>Hₐ</em>: The mean respiration rate of students is less than 32, i.e. <em>μ</em> < 32.

The sample mean  respiration rate of students is 31.3.

According to the claim the sample mean is less than 32.

The sample mean value is not unusual if the claim is true, and the sample mean value is also not unusual if the claim is false.

Thus, there is not sufficient evidence to support the claim.

7 0
3 years ago
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