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2 years ago

Please help it’s easy I think

Mathematics

1 answer:

Nikitich [7]2 years ago

4 0

The frequency of revision times is given by the product of the frequency

density value and the class width.

Correct response:

The number of students are <u>72 students</u>

<h3>Methods of calculation using a histogram</h3>

The estimate of the number of students who revised for less than 45

minutes is given by the area, <em>A,</em> under the histogram to the left of the 45

minute mark as follows;

Frequency, f = Frequency density × Class width

Number of students = ∑f

Therefore;

A = 5 × 2 + 10 × 2.2 + 20 × 1.6 + 10 × 0.8 = 72

The number of students that revised for less than 45 minutes = <u>72 </u>students

Learn more about histograms here:

brainly.com/question/17139138

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Mr.Montgomery's class, there are 8 boys and 12 girls.If Mr.Montgomery selects 1 student from his class at random, what is the pr

Gnoma [55]

Probability=number of specific outcomes / total possible outcomes

P(g)=12/(12+8)

P(g)=12/20

P(g)=3/5

7 0

2 years ago

Find the measures of an interior angle and an exterior angle of a regular 16-gon

Anastasy [175]

Answer:

2520°

Step-by-step explanation:

The sum of the angles in any triangle is 180°

shape. sides. triangles. sum int angles.

triangle. 180×1=180°

quad. 180×2=360°

pentagon. 180×3=540°

n-sides. n( n−2) 180(n−2)

16-sides. 180×14=2520°

7 0

3 years ago

How can I find the exact distance between the points(√7,-√2)and (4√7,5√2)

chubhunter [2.5K]

$\bf \textit{distance between 2 points}\\ \quad \\
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
% (a,b)
&({{ \sqrt{7}}}\quad ,&{{ -\sqrt{2}}})\quad 
% (c,d)
&({{4\sqrt{7}}}\quad ,&{{ 5\sqrt{2}}})
\end{array}~~~
% distance value
d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2}
\\\\\\
$

$\bf d=\sqrt{[4\sqrt{7}-\sqrt{7}]^2~+~[5\sqrt{2}-(-\sqrt{2})]^2}
\\\\\\
d=\sqrt{(4\sqrt{7}-\sqrt{7})^2~+~(5\sqrt{2}+\sqrt{2})^2}\implies d=\sqrt{(3\sqrt{7})^2~+~(6\sqrt{2})^2}
\\\\\\
d=\sqrt{3^2\cdot 7~~+~~6^2\cdot 2}\implies d=\sqrt{63+72}\implies d=\sqrt{135}
\\\\\\
\begin{cases}
135=5\cdot 3\cdot 3\cdot 3\\
\qquad 5\cdot 3^2\cdot 3\\
\qquad 15\cdot 3^2
\end{cases}\implies d=\sqrt{15\cdot 3^2}\implies d=3\sqrt{15}$

8 0

3 years ago

It's a PEMDAS question

monitta

[3 * (2 + 4)] - 4

Solve inside the brackets first.
Solve the parentheses inside the brackets, (2 + 4).

[3 * (6)] - 4

Now solve 3 * 6.

18 - 4

18 - 4 = 14, so your answer is:

4 0

3 years ago

Read 2 more answers

A statistics professor drew a random sample of 81 observations and found that x with bar on top equals 62 s equals 15. Estimate

ratelena [41]

Answer:

LCL = 59.26 to two decimal places

Step-by-step explanation:

Here, we want to estimate the LCL of the population mean with 90% confidence

We proceed as follows;

Given alpha = 0.1, then Z(0.05)=1.645 (from standard normal table), s = 15

Mathematically;

LCL =x_bar -Z*s/√( n)= 62 - (1.645 * 15)/√81

LCL = 62- (24.675)/9 = 59.2583

LCL = 59.26 to two decimal places

3 0

2 years ago