What is 20/40 as a decimal

The dual bar chart shows the hair colour of boys and girls in a year group. What fraction of the red haired students are boys? G

Step2247 [10]

Answer:

$\frac{3}{4}$

Step-by-step explanation:

Total red haired students = 15+5 = 20

Boys = 15

Fraction:

=> $\frac{15}{20}$

In simplest form:

=> $\frac{3}{4}$

3 0

3 years ago

What is the exponent in the power of 10?

Arisa [49]

X^10 the exponent would be 10

4 0

3 years ago

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 3.25 as a mixed number in simplest form.

snow_tiger [21]

3.25 can be re-written as;
=3+0.25
Converting the decimal to a fraction gives;
3+ $\frac{25}{100}$
=Simplify the fraction;
3+ $\frac{1}{4}$
The final answer is;
3 $\frac{1}{4}$

4 0

3 years ago

Read 2 more answers

An airline promotion to business travelers is based on the assumption that two-thirds of business travelers use a laptop compute

skad [1K]

Answer:

a

The null hypothesis is $H_o : p = 0.67$

The alternative hypothesis is $H_a : p \ne 0.67$

b

The sample proportion is $\^ p = 0.65$

Step-by-step explanation:

From the question we are told that

The sample size is n = 546

The number of people that use a laptop overnight is $k = 355$

The population proportion is $p = \frac{2}{3} = 0.67$

Generally

The null hypothesis is $H_o : p = 0.67$

The alternative hypothesis is $H_a : p \ne 0.67$

Gnerally the sample proportion is mathematically represented as

$\^ p = \frac{ k}{n}$

=> $\^ p = \frac{ 355}{546}$

=> $\^ p = 0.65$

4 0

4 years ago