Answer:
The jar of chermical contains 66g of Zinc.
Step-by-step explanation:
The ratio of Zinc to Copper is 3 : 13
A jar of the chemical contains 286g of copper.
Let the mass of the Zinc be xg.
=
x = = 66g
So the jar of chemical contains 66g of Zinc.
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%.