2800 + 1.18x = y
x = monthly sales
y = monthly income
y needs to be at least 6400 so that means;
2800 + 1.18x ≥ 6400
1.18x ≥ 6400 - 2800
x ≥ (6400 -2800) / 1.18
x ≥ 3050
So she needs to earn at least 3050, which means <span>≥ 3050</span>
No, there is significant difference in the use of e readers by different age groups.
Given sample 1 ( 29 years old)
=628,
=7%, sample 2( 30 years old)
=2309,
=0.11.
We have to first form hypothesis one null hypothesis and other alternate hypothesis.
π1-π2=0
π1-π2≠0
α=0.05
Difference between proportions 

The pooled proportion needed to calculate standard error is:

=(44+254)/(628+2309)
=0.10146
The estimated standard error of difference between means is computed using the formula:

=
=
=
=0.01315
Z= Pd-(π1-π2)/
=-0.04-0/0.013
=-3.0769
This test is a two tailed test so the p value for this test is calculated as (using z table)
p value:2 P(Z<-3.0769)
=2*0.002092
=0.004189
P value< significance level of 5%.
Hence there is enough evidence to show the claim that there is a significant difference in the use of e readers by different age groups.
Learn more about hypothesis at brainly.com/question/11555274
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Question is incomplete as it also includes:
Significance level of 5%.
Answer:
27
Step-by-step explanation:
6f - 3g + 4h
6(2) - 3(-1) + 4(3)
12 + 3 + 12
27
Ok so I uploaded the picture of how to do the promblem step by step so you know :)
Answer-
The number is 5
Explanation-
let the number be x
according to the condition
2x-(x-7)= 12
2x-x+7=12
x+7=12
x+7-7=12-7
x=5
therefore the required number is 5