9-b and the multiplicative inverse of 9

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

The figure below is the graph of the dimensions of a rectangle whose adjacent side lengths exhibit Inverse Variation (1,4) (2,2)

Stells [14]

Answer: true

Step-by-step explanation:

6 0

2 years ago

What is the value of x in the figure below? In this diagram, △ABD~△CAD.

morpeh [17]

Given:

Given that the triangles ABD and CAD are similar.

The length of AB is 12.

The length of BD is x.

The length of AC is 27.

We need to determine the value of x.

Value of x:

Let us use the leg rule to determine the value of x.

Thus, we have;

$\frac{BC}{AB}=\frac{AB}{BD}$

Substituting the values, we get;

$\frac{27}{12}=\frac{12}{x}$

Cross multiplying, we get;

$27x=12\times 12$

$27x=144$

Dividing both sides by 27, we have;

$x=\frac{16}{3}$

Thus, the value of x is $\frac{16}{3}$

Hence, Option D is the correct answer.

7 0

2 years ago

john is thinking of a number in the hundred thousands.The first digit is equal to the number of digits in the number.The number

scoundrel [369]

36.3 Johns number sub or add or divid or multication

5 0

3 years ago

Sum to n terms the series 7 +77 +777

julia-pushkina [17]

Answer:

Step-by-step explanation:

=7 (1+11+111+1111......n)

=7/9 (9+99+999+9999....n)

=7/9 ((10-1)+(10^2-1)+(10^3-1)+....n)

=7/9 ((10+10^2+10^3...n)-(1+1+1+1.....n))

=7/9 ((10 (10^n-1)/(10-1))-n)

4 0

3 years ago