Write and solve an equation of ratios, as follows:
15 250
----- = ------- = 10/12.
x 300
Then 15(12) = 10x, and x = 18. The company could well predict that 18 out of the 300 phones it sells in July will be defective, based upon past history.
Answer:
0.80589
Step-by-step explanation:
So all of the numbers of correct answers less than 4 are 0,1,2,3
We need to calculate the probability for each separately and then add them together.
To find the probability we have to first find the combination. We know that there’s n=8 trials and that p=0.3. So 1-0.3 gives us 0.7.
The combination formula is: ! / (!(−)!)
So the n would always =8, and the r would be 0,1,2,3. So you would have to calculate it for 0,1,2,3 Separately. This can be done by hand or you can use a simple combinations calculator online.
For 0;
The combination is 1,
1 x 0.3^0 x 0.7^8-0 =
0.057648
For 1;
The combination is 8,
8 x 0.3^1 x 0.7^8-1 =
0.19765
For 2;
The combination is 28
28 x 0.3^2 x 0.7^8-2 =
0.296475
For 3;
The combination is 56
56 x 0.3^3 x 0.7^8-3 =
0.254122
All that’s left is to add these four numbers;
0.057647 + 0.19765 + 0.296475 + 0.254122 = 0.80589
The value of the z score is 1.03.
According to the statement
we have given that the value of mean and standard deviation and we have to find the value of the z score.
So, For this purpose we know that the
Z-score indicates how much a given value differs from the standard deviation. The Z-score, or standard score, is the number of standard deviations a given data point lies above or below mean.
And the given values are:
mean value = 69 inches
s.d value = 2.8 inches
And the value of x is 71.9 inches.
So, The Z score is
z = x - mean / standard deviation
substitute the values in it then
z = 71.9 - 69 / 2.8
then
z = 2.9 /2.8
z = 1.03
So, The value of the z score is 1.03.
Learn more about Z Score here
brainly.com/question/25638875
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