The confidence interval formula is computed by:
Xbar ± Z s/ sqrt (n)
Where:
Xbar is the mean
Z is the z value
S is the standard deviation
N is the number of samples
So our given are:
90% confidence interval with a z value of 1.645
Sample size 40, 45
Mean 180, 179
Standard deviation 2, 4
So plugging that information in the data will give us a
confidence interval:
For 1:
Xbar ± Z s/ sqrt (n)
= 180 ± 1.645 (2 / sqrt (40))
= 180 ± 1.645 (0.316227766)
= 180 ± 0.520194675
= 179.48, 180.52
For 2:
Xbar ± Z s/ sqrt (n)
= 179 ± 1.645 (4 / sqrt (45))
<span>= 179 ± 1.645 (0.596284794)</span>
therefore, the answer is letter b
Hey there!
<span>Here are the steps involved:
</span>
1.Change 65% into a decimal. Move the decimal two places to the left and you get 0.65.
2. Multiply 0.65 by 50.
<span>140 x 0.65 = 91.
3. Since you are decreasing 140 by 65%, subtract 140 by 91.
140-91= 49
</span><span>(If you feel that my answer has helped you, please consider rating it and giving it a thank you! Also, feel free to make the best answer, the brainliest answer!)
</span>
<span>Thank you! :D</span>
The student had a 40% error estimate
Answer:
c
Step-by-step explanation:
i am 99.99% sure it is c
