Question

# Compute a 95% confidence interval for the quantitative variable for the sales data set and interpret...

Compute a 95% confidence interval for the quantitative variable for the sales data set and interpret that interval.

 Sales (Y) Mean 41.89 Standard Error 0.84 Median 43 Mode 44 Standard Deviation 8.39 Sample Variance 70.32 Kurtosis 1.66 Skewness -0.45 Range 46 Minimum 21 Maximum 67 Sum 4189 Count 100

We are asked to calculate and interpret the 95% confidence interval given the following data

Mean= 41.89

Standard Error= 0.84

Median= 43

Mode= 44

Standard Deviation= 8.39

Sample variance =70.32

Kurtosis= 1.66

Skewness = -0.45

Range= 46

Minimum= 21

Maximum= 67

Sum= 4189

Count= 100

The formula for 95% confidence interval for mean is,

(Mean-Z*Standard Error, Mean+Z*Standard Error)

where Z is the critical value at 5% significance level

The critical value at 5% significance level is 1.96.

Substituting the values in the given formula we get,

(41.89-1.96*0.84, 41.89+1.96*0.89)

=>(40.2436, 43.5364) is the required 95% confidence interval for the true mean of sales.

This means that we are 95% sure that the true average(or mean) of sales lies in the interval 40.2436 and 43.5364.

#### Earn Coins

Coins can be redeemed for fabulous gifts.