Respuesta :
Answer:
Check the explanation
Step-by-step explanation:
Given:
Claim: According to Mars, Inc., 20% of all M&Ms produced are blue.
that is: p = proportion of M&Ms are blue = 0.20
Sample size = n = 50
x = Number of M&Ms are blue = 14
Step 1) State H0 and H1:
H_{0}: p = 0.20 Vs H_{1}: p \neq 0.20
Step 2) Test statistic:
P-p px(1-p)
where
[tex]\hat{p}=\frac{x}{n} = \frac{14}{50}[/tex] = 0.28
thus
P-p px(1-p)
z= [tex]\frac{0.28 - 0.20}{\sqrt{\frac{0.20 \times (1-0.20)}{50}}}[/tex]
z=[tex]\frac{0.08 }{\sqrt{\frac{0.20 \times 0.80}{50}}}[/tex]
z= [tex]\frac{0.08 }{\sqrt{ 0.0032 }}[/tex]
z= [tex]\frac{0.08 }{ 0.0565685 }[/tex]
z= 1.41
Step 3) Find z critical value:
Since level of significance is not given , we use level of significance = g= 0,05
Look in z table for area = 0.0250 or its closest area and find z value
Area 0.0250 corresponds to -1.9 and 0.06
thus z critical value = -1.96
Since this is two tailed test, we have two z critical values: ( -1.96 , 1.96)
Step 4) Decision Rule:
Reject null hypothesis ,if z test statistic value < z critical value =-1.96 or z test statistic value > z critical value = 1.96 , otherwise we fail to reject H0.
That is rejection region is: z < -1.96 or z > 1.96.
Since z test statistic value = z= 1.41 is between z critical values: ( -1.96 , 1.96), that is z test statistic value = z= 1.41 does not fall in the rejection region, we fail to reject H0.
Step 5) Conclusion:
At 0.05 level of significance, we do not have sufficient evidence to reject the claim that: 20% of all M&Ms produced are blue.
that is: Mars, Inc. claim that 20% of all M&Ms produced are blue is true.