Question

Match the margin of error for an 80% confidence interval to estimate the population mean with sigma σ equals=50

with its corresponding sample sizes.

Question 5 options:

a.) 8.07. 1.) n= 34

b.) 9.45 2.) n= 46

c.) 10.99 3.) n= 63

Answer 1

Solution :

Population standard deviation = = 50

1) Sample size = n =34

At 80% confidence level

= 1-0.80% =1-0.80 =0.20

/2 =0.20/ 2= 0.10

Z/2 = Z0.10 = 1.28

Z/2 = 1.282
Margin of error = E = Z/2 * ( /n)

= 1.282 * ( 50 /   34)

=10.99

Answer c) 10.99 is correct

2)

Sample size = n =46

Z/2 = 1.282
Margin of error = E = Z/2 * ( /n)

= 1.282 * ( 50 /   46)

=9.45

Answer b)9.45 is correct

3)

Sample size = n = 63

Z/2 = 1.282
Margin of error = E = Z/2 * ( /n)

= 1.282 * ( 50 /  63)

= 8.07

Answer a) 8.07 is correct