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3 years ago

If you add 15 to 3 times the mystery number you get 78 was the mystery number

1 answer:

8 0

So the equation looks like this : 15*3x=78
subtract 15 from both sides: -15 -15
then divide by 3 from both sides
to isolate the variable: 3x=63
3/3x=63/3
x=21 (your mystery number is 21)

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A survey of 700 adults from a certain region asked, "What do you buy from your mobile device?" The results indicated that 59%

Kryger [21]

Answer:

a) the test statistic z = 1.891

the null hypothesis accepted at 95% level of significance

b) the critical values of 95% level of significance is zα =1.96

c) 95% of confidence intervals are (0.523 ,0.596)

Step-by-step explanation:

A survey of 700 adults from a certain region

Given sample sizes $n_{1} = 400 and n_{2} = 300$

Proportion of mean $p_{1} = \frac{236}{400} = 0.59 and p_{2} = \frac{156}{300} = 0.52$

Null hypothesis H0 : assume that there is no significant difference between males and women reported they buy clothing from their mobile device

p1 = p2

Alternative hypothesis H1:- p1 ≠ p2

a) The test statistic is

$Z = \frac{p_{1} -p_{2} }{\sqrt{pq(\frac{1}{n_{1} }+\frac{1}{n_{2} )} } }$

where $p = \frac{n_{1}p_{1} +n_{2}p_{2} }{n_{1}+n_{2}}= \frac{400X0.59+300X0.52}{700}$

on calculation we get p = 0.56

now q =1-p = 1-0.56=0.44

$Z = \frac{p_{1} -p_{2} }{\sqrt{pq(\frac{1}{n_{1} }+\frac{1}{n_{2} )} } }\\ =\frac{0.56-0.52}{\sqrt{0.56X0.44}(\frac{1}{400}+\frac{1}{300} }$

after calculation we get z = 1.891

b) The critical value at 95% confidence interval zα = 1.96 (from z-table)

The calculated z- value < the tabulated value

therefore the null hypothesis accepted

conclusion:-

assume that there is no significant difference between males and women reported they buy clothing from their mobile device

p1 = p2

c) 95% confidence intervals

The confidence intervals are P± 1.96(√PQ/n)

we know that = $p = \frac{n_{1}p_{1} +n_{2}p_{2} }{n_{1}+n_{2}}= \frac{400X0.59+300X0.52}{700}$

after calculation we get P = 0.56 and Q =1-P =0.44

Confidence intervals are ( P- 1.96(√PQ/n), P+ 1.96(√PQ/n))

now substitute values , we get

( 0.56- 1.96(√0.56X0.44/700), 0.56+ 1.96(0.56X0.44/700))

on simplification we get (0.523 ,0.596)

Therefore the population proportion (0.56) lies in between the 95% of confidence intervals (0.523 ,0.596)

3 0

3 years ago

Write 5numbers 8digit long

Virty [35]

12345678
23456789
34567890
45678901
56789012

6 0

3 years ago

sean and morgan walked from the same location sean walked 5 1/2 blocks north and 3 1/4 blocks east morgan walked 3 1/4 blocks ea

Yakvenalex [24]

Answer:

Step-by-step explanation:

5 1/2 + 4 1/2 = 10

4 0

3 years ago

Question in pic. please help!

ArbitrLikvidat [17]

Answer:

Arranging from longest (at top) to shortest (at bottom)

Step-by-step explanation:

We need to place the sides of triangle DE, DF and EF from longest to shortest.

The triangle has longest side that is opposite to the largest angle

We know two angles < E= 61° , <F= 59° we need to find <D

Sum of angles of triangle = 180°

So, 61°+59°+<D=180°

120°+<D=180°

<D=180°-120°

<D=60°

So, the largest angle is <E= 61°

The longest side must be opposite to <E so, the side is DF

The second largest angle is <D=60° so, second side will be EF

The smallest angle is <F=59° so, third (shortest) side will be DE

Arranging from longest (at top) to shortest (at bottom)

7 0

3 years ago

What is an equation of the line that passes through the points (-8, 1) and(7,1)?

likoan [24]

Answer:

y=1

Step-by-step explanation:

you can use those points to find the slope

use the equation $\frac{y_{1} - y_{2}}{x_{1}-x_{2}}$ then plug in the numbers

so (1-1)/(-8-7) = 0/15 so the slope is zero meaning it is a horizontal line which we can tell logically because the y coordinates of both points are 1.

so if you plug those numbers into the formula y=mx+b where m is slope and b is the y intercept then

you get y=0*x+1

then 0*x is just zero and it goes away so the equation for this line is y=1

Hope this helps! :)

8 0

3 years ago

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