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3 years ago

12

Rob's first four test scores are 80, 85, 100 and 85. What does he have to score on the last test in order to have a test average

of 90?

1 answer:

faust18 [17]3 years ago

6 0

Answer:

100

Step-by-step explanation:

85 +80+100+85+x(the unknown),/the number of numbers ie 5

350+x/5=90

350+x=90 * 5

350+x=450

x=450-350

x=100

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Multiply the polynomial (x+3)(x+4)<br><br> A)x^2+7<br> B)x^2+12<br> C)x^2+7x+12

LekaFEV [45]

Your answer is option C: <span><span>x<span><span>^2</span><span></span></span></span>+7x+1<span>2</span></span>

3 0

3 years ago

Denise is a professional swimmer who trains, in part, by running. she would like to estimate the average number of miles she run

SSSSS [86.1K]

Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval

The degrees of freedom is
df = n-1 = 19

We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.

The 99% confidence interval is
xbar +/- t*(s/√n)

t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)

Answer: The 99% confidence interval is (15.07, 19.93)

4 0

4 years ago

Find the coordinates of the midpoint of AS if A(-4, 7) and S(5,3).

lesya692 [45]

Answer:

The answer is

<h2> $( \frac{1}{2} \: , \: 5)$ </h2>

Step-by-step explanation:

The midpoint M of two endpoints of a line segment can be found by using the formula

<h3> $M = ( \frac{x1 + x2}{2} , \: \frac{y1 + y2}{2} )$ </h3>

where

(x1 , y1) and (x2 , y2) are the points

From the question the points are

A(-4, 7) and S(5,3)

The midpoint is

<h3> $M = ( \frac{ - 4 + 5}{2} , \: \frac{7 + 3}{2} ) \\ = ( \frac{1}{2} , \: \frac{10}{2} )$ </h3>

We have the final answer as

<h3> $( \frac{1}{2} \: , \: 5)$ </h3>

Hope this helps you

8 0

3 years ago

Read 2 more answers

Maxim and Salma were asked to find an explicit formula for the sequence 54,63,72,81,... Maxim said the formula is f(n)=54+9n Sal

Sever21 [200]

ANSWER

The explicit rule is

$f(n) = 45+9n$

EXPLANATION

The given sequence is :

54,63,72,81,...

The first term of this sequence is

$a = 54$

The common difference is

$d =63 - 54 = 9$

The explicit rule is given by:

$f(n) = a + d(n - 1)$ $f(n) = 54+9(n -1 )$

We expand to get:

$f(n) = 54+9n -9$

$f(n) = 45+9n$

None of them is correct .

8 0

4 years ago

Yulet rolls 2 fair dice and adds the results from each.

antiseptic1488 [7]

2,4,6,8,10,12,14,16,18,20,22,24!.. so 2 x 12= (24).....

3 0

3 years ago