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2 years ago

An equation was used to predict possible sales of phones for 6 months. The actual sales of phones are also listed.

Mathematics

2 answers:

Grace [21]2 years ago

5 0

Answer with Step-by-step explanation:

Residual is calculated by the difference between actual value and the predicted value.

Actual sales Predicted sales Residual

55 40 15

150 150 0

325 300 25

510 500 10

780 800 -20

990 1000 -10

Sum of residuals=15+0+25+10-20-10

=20

Hence, sum of residuals is:

LekaFEV [45]2 years ago

3 0

They were up 15+0+25+10-20-10=20. The sum was 20 :)

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Using Normal Distribution to Analyze Data Martin suspects that people carry less cash with them than they used to because of cre

jek_recluse [69]

Answer:

Step-by-step explanation:

Sample size = 95

X=cash carried by the persons

x bar = 8.00

s = sample std dev = 2.50

Std error = $\frac{s}{\sqrt{n} } =\frac{2.5}{\sqrt{95} } \\=0.2565$

Hence Z score would be

$\frac{x-8}{0.2565}$

$a) P(X$

-0.00

b) $P(9$

c) 95% conf interval margin of error = ± $1.96*0.2565$

=±0.54782

Confi interval = (8-0.5027, 8+0.5027)

= (7.4923, 8.5027)

C)If conf level increases, then width of interval would increase since critical value would increase.

If sample size increases std error would decrease and hence margin of error.

So interval would decrease.

3 0

1 year ago

The given equation has been solved in the table. In which step was the subtraction property of equality applied?

atroni [7]

Answer:

Option (D)

Step-by-step explanation:

Subtraction property of equality tells that whatever subtracted from one side of the equation must be subtracted from the other side.

If x + 2 = 2,

By the property of subtraction of equality,

x + 2 - 2 = 2 - 2

x = 0

But in the given question,

$\frac{x}{2}-7=-7$

$\frac{x}{2}-7+7=-7+7$

shows the addition property of equality in step (2)

Therefore, subtraction property of equality was not applied.

Option (D) will be the answer.

5 0

1 year ago

A group of adults and students went on a class trip to Washington, DC. The number of male students was 1 more than 7 times the n

AVprozaik [17]

X number of male students
Y number of female students
Z number of the adults
X=(1 + 7)Z=8Z
Y= X/2
X +Y +Z = 82
8Z +8Z/2 +Z=82 implies Z=82/26=3.1
so we take Z= 3

X= 24
and Y = 12

5 0

2 years ago

Last month, Dory biked 11 Times as many miles as Karly. Together they biked a total of 156 miles. How many more miles did Dory b

salantis [7]

13 more miles. You can use long division.

4 0

2 years ago

Consider a data set with at least three data values. Suppose the highest value is increased by 10 and the lowest is decreased by

bulgar [2K]

Answer:

a. Mean doesn't change.

b. Median doesn't change.

c. Mode can change.

Step-by-step explanation:

Let us assume the data set with 10 observations

{2,6,4,3,2,6,4,9,4,7}.

Arranging data set in ascending order

{2,2,3,4,4,4,6,6,7,9}

mean=2+2+3+4+4+4+6+6+7+9/10=4.7

median

n/2=10/2=5 is an integer so,

median= average of n/2 and n/2 +1

median= (5th value+6th value)/2

median=(4+4)/2=8/2=4

Mode

The most repeated value is 4. So, mode is 4 for assumed data.

Increasing highest value by 10 and decreasing lowest value by 10

{-8,2,3,4,4,4,6,6,7,19}

mean=-8+2+3+4+4+4+6+6+7+19/10=4.7

Mean doesn't change

median

n/2=10/2=5 is an integer so,

median= average of n/2 and n/2 +1

median= (5th value+6th value)/2

median=(4+4)/2=8/2=4

Median doesn't change

Most occurring value is still 4. But mode can change if the value the highest value becomes most concurring value.

5 0

2 years ago

Read 2 more answers