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3 years ago

Help plz I need to have this quick

Mathematics

1 answer:

Ivenika [448]3 years ago

5 0

Answer:

A and D are 87 degrees

C is 28 degrees

and B is 65 degrees

Step-by-step explanation:

28 degrees and c are congruent

a and d are congruent

65 degrees and b are cungruent

B(65)+28+D= 180

65+28= 93

93+D=180

D=87

A=D(87)

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I am a two digit odd number I am a factor of 84 and also a multiple of 7 what number am I?

cricket20 [7]

Answer:

Step-by-step explanation:

2 digit number| 2 and 1 that's 2 digits

factor of 84 21 x 4=84 21 42 63 84

multiple of 7 7 x 3=21

8 0

3 years ago

The football coach randomly selected 10 players and timed how long each player took to perform a certain drill. The result has a

Volgvan

Answer:

The 95% confidence interval for the mean time for all players, in minutes, is: (7.95, 11.01).

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

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

df = 10 - 1 = 9

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 9 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.95}{2} = 0.975$ . So we have T = 2.2622.

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.2622\frac{2.14}{\sqrt{10}} = 1.53$

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

The lower end of the interval is the sample mean subtracted by M. So it is 9.48 - 1.53 = 7.95 minutes.

The upper end of the interval is the sample mean added to M. So it is 9.48 + 1.53 = 11.01 minutes.

The 95% confidence interval for the mean time for all players, in minutes, is: (7.95, 11.01).

4 0

3 years ago

This exercise provides information about data in a survey of students. Of the students who identified their class year in the su

shusha [124]

Answer: $\hat{p}\approx0.228$

Step-by-step explanation:

Given : This exercise provides information about data in a survey of students.

Of the students who identified their class year in the survey, 82 were first years, 219 we're sophomores, 28 we're juniors, and 61 were seniors.

Total students sampled = $82+219+28+61=390$

Number of upper class students (juniors or seniors.) = $28+61=89$

Now, the proportion who are upper class students (juniors or seniors.) will be :-

$\hat{p}=\dfrac{\text{Number of upper class students}}{\text{Total students}}\\\\=\dfrac{89}{390}=0.228205128205\\\\\approx0.228\ \ [ \text{Round to three decimal places.}]$