(a) If mental arithmetic is taken as a measure of intelligence then what mental arithmetic score would a child with an IQ of 100 be expected to obtain?
One - Sample Statistics
N
Mean
Std. Deviation
Std. Error Mean
mental arithmetic scores
320
7.51
3.231
.181
From the results of the above mentioned descriptive statistics, the mean of mental arithmetic scores that is used in analyzing the data is given. The most essential and critical values of the One - Sample Statistics is the mean and the standard deviation of the variables, which are imperative to study. Moreover, these values provide the data accuracy; in addition to this, it is also found that observed that the mean of mental arithmetic scores is 7.51 with the standard deviation of 3.2.
One - Sample Test
Test Value = 100
t
df
Sig. (2 - tailed)
Mean Difference
95 % Confidence Interval of the Difference
Lower
Upper
mental arithmetic scores
- 512.108
319
.000
- 92.494
- 92.85
- 92.14
From the above table it can be observed that the significance level is less than 0.05 indicating that there is zero probability that the mean difference of - 93.494 has a zero probability of occurring.
(b) Using the standard deviation (z-score) what proportion of children should have scores between 4.0 and 8.0?
Keeping in view, the standard deviation (z-score), it can be said that there is zero probability that the children will have scores between 4.0 and 8.0, as the standard deviation is 3.231 with the mean value of 7.51.
(c) Use 'frequencies' to determine the mean, median, mode and quartiles for the mental arithmetic score
Statistics
mental arithmetic scores
N
Valid
320
Missing
29
Mean
7.51
Median
7.00
Mode
6
Percentiles
25
5.00
50
7.00
75
10.00
(d) Compute correlations between these variables and comment on the meaning of the correlation between the eowpvt-r and the Crichton scores
Correlations
standard scores eowpvt
crichton vocabulary scores
mental arithmetic scores
standard scores eowpvt
Pearson Correlation
1
.660 **
.352 **
Sig. (2 - tailed)
.000
.001
N
80
80
80
crichton vocabulary scores
Pearson Correlation
.660 **
1
.536 **
Sig. (2 - tailed)
.000
.000
N
80
320
320
mental arithmetic scores
Pearson Correlation
.352 **
.536 **
1
Sig. (2 - tailed)
.001
.000
N
80
320
320
**. Correlation is significant at the 0.01 level (2 - tailed).
From the given correlation table, it can be observed that there is correlation between standard scores eowpvt and crichton vocabulary scores. The basis of this statement is that the level of significance indicates that it is statistically significant as it below 0.5 which represents the significance. Moreover, the Pearson correlation coefficient indicates is in positive that is 0.66, this reflects that there is positive correlation between the standard scores eowpvt and crichton vocabulary scores.