All categories

3 years ago

In a class of 32 students

Mathematics

1 answer:

Veseljchak [2.6K]3 years ago

6 0

Answer:

1.48 m

Step-by-step explanation:

In a class of 32 students

the mean height of the 14 boys is 1.56 meters.

the mean height of all 32 students is 1.515 meters.

Total number of students = 32

Mean height of all students = 1.515

We can obtain the sum of all student's height :

Number if students * mean height

= 32 * 1.515

= 48.48

Number of boys = 14

Mean height of boys = 1.56m

We can obtain the sum of all boys height :

Number if students * mean height

= 14 * 1.56

= 21.84

Number of girls :

All students - Number of boys

32 - 14 = 18

Sum of girls height :

48.48 - 21.84 = 26.64

Mean height of girls :

Sum of girls height / Number of girls

26.64 / 18

= 1.48 m

You might be interested in

A sample of 20 account balances of a credit company showed an average balance of $1,170 and a standard deviation of $125. You wa

Lady_Fox [76]

Answer:

The P-value for this test is P=0.2415.

Step-by-step explanation:

We have to perform an hypothesis testing on the mean of alla account balances.

The claim is that the mean of all account balances is significantly greater than $1,150.

Then, the null and alternative hypothesis are:

$H_0: \mu=1150\\\\H_a: \mu>1150$

The sample size is n=20, with a sample mean is 110 and standard deviation is 125.

We can calculate the t-statistic as:

$t=\dfrac{\bar x-\mu}{s/\sqrt{n}}=\dfrac{1170-1150}{125/\sqrt{20}}=\dfrac{20}{27.95}=0.7156$

The degrees of freedom fot this test are:

$df=n-1=20-1=19$

For this one-tailed test and 19 degrees of freedom, the P-value is:

$P-value=P(t>0.7156)=0.2415$

8 0

4 years ago

A plumbers bill is £463.20 plus VAT. The current rat of VAT is 20%. What is the actual cost of work done?

Mila [183]

£555.84

1% of the original value ×20 is £92.64. Add that to the original value (£463.20)

8 0

3 years ago

40 POINTS AND BRAINLIEST IF RIGHT!!! Which table of values is shown on the graph?

slavikrds [6]

Answer:

It is the first choice, where 3 pennies are 7.5 grams

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

What word problem could be used for the 2 step equation .5(x+40)=200

Fiesta28 [93]

Since multiplying by 0.5 is the same as dividing by 2, the problem is described by the sentence

"Half the sum of a number and 40 equals 200"

5 0

3 years ago

Read 2 more answers

In right △ABC with right angle B, m∠A=(3x−8)° and m∠C=(x−2)°.

julsineya [31]

Answer:

<A = 67

Step-by-step explanation:

The three angles of a triangle add up to 180 degrees. We know a right angle is 90 degrees.

<A + <B + <C = 180

3x-8 + 90 + x-2 =180

Combine like terms

4x-10+90 = 180

4x+80 =180

Subtract 80 from each side

4x+80-80=180-80

4x=100

Divide each side by 4

4x/4 = 100/4

x=25

But we want to know <A

<A = 3x-8

Substitute x=25

=3(25) -8

=75-8

= 67

6 0

4 years ago

Read 2 more answers