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Temka [501]
3 years ago
12

A total of 50 juniors and seniors were given a mathematics test. The 35 juniors attained an average score of 80 while the 15 sen

iors attained an average of 70. What was the average score for all 50 students who took the test?
Mathematics
1 answer:
Alik [6]3 years ago
8 0

Answer:

77

Step-by-step explanation:

Firstly, we need to calculate the total score of the junior students and the total score of the senior students.

The total score of the junior students is 35 * 80 = 2,800

The total score of the senior students is 15 * 70 = 1050

The total score is thus 2,800 + 1,050 = 3,850

The average score of the 50 students is thus 3,850/50 which equals 77

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Please help, thanks in advance
avanturin [10]

Answer:

D. \frac{45a^{16}c^{34}}{b^{27}}

Step-by-step explanation:

Here you are...

Hope this helps! Brainliest would be much appreciated! Have a great day! :)

3 0
2 years ago
Determine the margin of error for a 90% confidence interval to estimate the population mean when s = 40 for the sample sizes bel
Ann [662]

Answer:

a) The margin of error for a 90% confidence interval when n = 14 is 18.93.

b) The margin of error for a 90% confidence interval when n=28 is 12.88.

c) The margin of error for a 90% confidence interval when n = 45 is 10.02.

Step-by-step explanation:

The t-distribution is used to solve this question:

a) n = 14

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 14 - 1 = 13

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 13 degrees of freedom(y-axis) and a confidence level of 1 - \frac{1 - 0.9}{2} = 0.95. So we have T = 1.7709

The margin of error is:

M = T\frac{s}{\sqrt{n}} = 1.7709\frac{40}{\sqrt{14}} = 18.93

In which s is the standard deviation of the sample and n is the size of the sample.

The margin of error for a 90% confidence interval when n = 14 is 18.93.

b) n = 28

27 df, T = 1.7033

M = T\frac{s}{\sqrt{n}} = 1.7033\frac{40}{\sqrt{28}} = 12.88

The margin of error for a 90% confidence interval when n=28 is 12.88.

c) The margin of error for a 90% confidence interval when n = 45 is

44 df, T = 1.6802

M = T\frac{s}{\sqrt{n}} = 1.6802\frac{40}{\sqrt{45}} = 10.02

The margin of error for a 90% confidence interval when n = 45 is 10.02.

3 0
2 years ago
Find the value of x and y. Triangle MNP = triangle TUS
xenn [34]

Answer:

x = 32, y = 51

Step-by-step explanation:

Since the triangles are congruent then corresponding sides and angles are congruent, that is

∠ U = ∠ N

∠ N = 180° - (142 + 24)° = 180° - 166° = 14° , then

2x - 50 = 14 ( add 50 to both sides )

2x = 64 ( divide both sides by 2 )

x = 32

and

NP = US

2x - y = 13

2(32) - y = 13

64 - y = 13 ( subtract 64 from both sides )

- y = - 51 ( multiply both sides by - 1 )

y = 51

3 0
2 years ago
What is the area of this composite figure?
VLD [36.1K]

Answer:

36.56

Step-by-step explanation:

the area of a circle is r^2×pi (here 2^2×pi) then add the area of the middle rectangle (so 4×6)

6 0
2 years ago
Colby and Sarah sold newspapers this past summer. Colby earned $4.50 for each newspaper he sold. Sarah's earnings were $35 less
Furkat [3]
Y represent the total number of newspapers sold by Colby.
5 0
3 years ago
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